HCHO2 and NaCHO2, and CH3NH2 and CH3NH3Cl can make buffer solutions. HCl and NaCl, and NH3 and NaOH cannot make buffer solutions.
Explanation:1. HCHO2 is formic acid, a weak acid, while NaCHO2 is the salt made from the anion of the weak acid (the formate ion [CHO2]). The combination of these two solutes would make a buffer solution.
2. HCl is a strong acid, not a weak acid, so the combination of these two solutes would not make a buffer solution.
3. CH3NH2 is methylamine, which is like NH3 with one of its H atoms substituted with a CH3 group. Because it is not listed in Table 12.8.1, we can assume that it is a weak base. The compound CH3NH3Cl is a salt made from that weak base, so the combination of these two solutes would make a buffer solution.
4. NH3 is a weak base, but NaOH is a strong base. The combination of these two solutes would not make a buffer solution.
Henry's law of partial pressures states that when a gas is in contact with a liquid, that gas will dissolve in the liquid in proportion to its partial pressure. henry's law of partial pressures states that when a gas is in contact with a liquid, that gas will dissolve in the liquid in proportion to its partial pressure.
a. True
b. False
Magnesium (mg) forms an oxide with one magnesium atom and one oxygen atom as its formula. which element below is likely to form an oxide with a similar 1:1 formula? silicon, si sodium, na aluminum, al calcium, ca
Answer:
Calcium will form similar kind of oxide.
Explanation:
Magnesium is an alkaline earth metal. It has two electrons in its valence shell and thus it can easily give these electrons to form dipositive ion.
Mg: 1s² 2s² 2p⁶ 3s²
Mg⁺²: 1s² 2s² 2p⁶ [full filled].
Now it will form monoxide with oxygen as: MgO
The calcium also belongs to same group and have two valence electrons in its outer shell and thus it can easily give these electrons to form dipositive ion.
Ca: [Ne] 3s² 3p⁶ 4s²
Ca⁺²: [Ne] 3s² 3p⁶ [full filled].
hence it will also form CaO.
For other elements
a) Silicon can form SiO₂
b) Sodium can form Na₂O
c) Aluminium can form Al₂O₃
A 92.0 ml volume of 0.25 m hbr is titrated with 0.50 m koh. calculate the ph after addition of 46.0 ml of koh at 25 ∘c.
After adding 46.0 mL of 0.50 M KOH to 92.0 mL of 0.25 M HBr, the solution is neutral and has a pH of approximately 7.
To determine the pH of the solution when 46.0 mL of 0.50 M KOH is added to 92.0 mL of 0.25 M HBr at 25°C, follow these steps:
Calculate the moles of HBr and KOH:
Moles of HBr: 0.25 M × 0.092 L = 0.023 moles
Moles of KOH: 0.50 M × 0.046 L = 0.023 moles
Determine the reaction completeness:
KOH completely neutralizes an equivalent amount of HBr (1:1 ratio):
0.023 moles of HBr neutralized by 0.023 moles of KOH.
Calculate the pH:
After the neutralization, there are no excess moles of acid (H+) or base (OH-), resulting in neutral pH.
The pH of the resulting solution is therefore approximately 7.
In summary, after adding 46.0 mL of 0.50 M KOH to 92.0 mL of 0.25 M HBr, the solution is neutral, with a pH of approximately 7
0 ml of 0.212 m naoh is neutralized by 13.6 ml of an hcl solution. the molarity of the naoh solution is
I believe the correct volume of 0.212 M NaOH is 25.0 mL and not 0 mL.
Since the reactants are strong base and a strong acid then this is an example of neutralization reaction. The balance chemical reaction is:
NaOH + HCl ---> NaCl + H2O
We can see from the reaction above that the ratio of NaOH to HCl is 1:1. Therefore,
number of moles HCl = (0.212 mol NaOH / L) * 0.025 L * (1 mol HCl / 1 mol NaOH)
number of moles HCl = 0.0053 mol HCl
Molarity is number of moles divided by volume in Liters, therefore the molarity of HCl solution is:
Molarity HCl = 0.0053 mol HCl / 0.0136 L
Molarity HCl = 0.390 M
One of the most common causes of inaccurate melting points is too rapid heating of the melting point bath. under these circumstances, how ill the observed melting point compare to the true melting point.
How many moles of NaCl are required to prepare 0.80 L of 6.4 M NaCl
0 ml of a 6.0 m hno3 stock solution is diluted using water to 100 ml. how many moles of hno3 are present in the dilute solution? 25.0 ml of a 6.0 m stock solution is diluted using water to 100 ml. how many moles of are present in the dilute solution? 6.0 moles 0.6 moles 0.15 moles 1.5 moles
[tex]\boxed{{\text{0}}{\text{.15 mol}}}[/tex] of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] is present in the dilute solution.
Further Explanation:
The proportion of substance in the mixture is called concentration. The most commonly used concentration terms are as follows:
1. Molarity (M)
2. Molality (m)
3. Mole fraction (X)
4. Parts per million (ppm)
5. Mass percent ((w/w) %)
6. Volume percent ((v/v) %)
Molarity is a concentration term that is defined as the number of moles of solute dissolved in one litre of the solution. It is denoted by M and its unit is mol/L.
The formula to calculate the molarity of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] solution is as follows:
[tex]{\text{Molarity of HN}}{{\text{O}}_3}\;{\text{solution}} = \frac{{{\text{Moles}}\;{\text{of}}\;{\text{HN}}{{\text{O}}_3}}}{{{\text{Volume }}\left( {\text{L}} \right){\text{ of}}\;{\text{HN}}{{\text{O}}_3}\;{\text{solution}}}}[/tex] …… (1)
Rearrange equation (1) to calculate the moles of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex].
[tex]{\text{Moles}}\;{\text{of}}\;{\text{HN}}{{\text{O}}_3} = \left( {{\text{Molarity of HN}}{{\text{O}}_3}\;{\text{solution}}} \right)\left( {{\text{Volume of}}\;{\text{HN}}{{\text{O}}_3}\;{\text{solution}}} \right)[/tex] …… (2)
The volume of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] solution is to be converted into L. The conversion factor for this is,
[tex]{\text{1 mL}} = {10^{ - 3}}\;{\text{L}}[/tex]
So the volume of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] solution is calculated as follows:
[tex]\begin{aligned}{\text{Volume of HN}}{{\text{O}}_{\text{3}}}\;{\text{solution}}&=\left( {{\text{25 mL}}}\right)\left({\frac{{{{10}^{ - 3}}\;{\text{L}}}}{{{\text{1 mL}}}}} \right)\\&=0.02{\text{5 L}}\\\end{aligned}[/tex]
The molarity of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] solution is 6M.
The volume of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] solution is 0.025 L.
Substitute these values in equation (2).
[tex]\begin{aligned}{\text{Moles}}\;{\text{of}}\;{\text{HN}}{{\text{O}}_3}&=\left( {{\text{6 M}}} \right)\left( {0.02{\text{5 L}}} \right)\\&=0.1{\text{5 mol}} \\ \end{aligned}[/tex]
The number of moles of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] in 25 mL solution is 0.15 mol.
Dilution is the conversion of a concentrated solution into a dilute solution with the addition of extra solvent but the amount of solute is unaltered. The change that arises is an increase in the volume of the solution.
In the given solution, dilution is done and the concentration of solution decreases during the process. But the number of moles of solute remains unaltered. Therefore the number of [tex]{\text{HN}}{{\text{O}}_{\text{3}}}[/tex] in the dilute solution is also 0.15 mol.
Learn more:
1. Calculation of volume of gas: https://brainly.com/question/3636135
2. Determine the moles of water produced: https://brainly.com/question/1405182
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Concentration terms
Keywords: molarity, HNO3, dilution, moles of HNO3, volume, solution, 0.15 mol, concentration, 25 mL, 6 M, concentrated solution, dilute solution.
A patient requires 36 mmol of phosphate and 90 meq of potassium in their pn. the pharmacy has stock solutions of potassium phosphate (3 mmol of phosphate and 4.4 meq potassium per ml) and potassium chloride (2 meq potassium/ml). how many milliliters of potassium chloride are required?
First, we need to calculate for the volume of potassium phosphate required to meet the desired phosphate level of 36 mmol.
V potassium phosphate = 36 mmol / (3 mmol / mL)
V potassium phosphate = 12 mL
This also contains potassium in the amounts of:
V potassium in potassium phosphate = (4.4 meq / mL) * 12 mL
V potassium in potassium phosphate = 52.8 meq
Therefore the lacking amount of potassium is 90 – 52.8 = 37.2 meq
This lacking potassium must be supplied by the potassium chloride. Calculating for volume of potassium chloride:
V potassium chloride = 37.2 meq / (2 meq / mL)
V potassium chloride = 18.6 mL (ANSWER)
To meet the patient's potassium requirement, 18.6 ml of potassium chloride solution is needed after considering potassium provided by the potassium phosphate solution. The total potassium needs are 90 meq, with 52.8 meq provided by 12 ml of potassium phosphate. The remaining 37.2 meq is met by administering 18.6 ml of potassium chloride.
To determine how many milliliters of potassium chloride (KCl) are needed, we first need to calculate the total potassium (K) requirement not met by the potassium phosphate (K₃PO₄) solution.
Step-by-Step Solution:
The patient needs 90 meq of potassium (K) in total.The potassium phosphate solution provides both potassium and phosphate, with 3 mmol of phosphate and 4.4 meq of potassium per ml.We need 36 mmol of phosphate, so we calculate the required volume of potassium phosphate solution:Thus, 18.6 ml of potassium chloride are required to meet the patient’s potassium needs.
How many grams of ko2 are needed to form 6.5 g of o2?
Answer: The mass of [tex]KO_2[/tex] needed is 19.3 grams.
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
Given mass of oxygen gas = 6.5 g
Molar mass of oxygen gas = 32 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of oxygen gas}=\frac{6.5g}{32g/mol}=0.203mol[/tex]
The chemical equation follows:
[tex]4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2[/tex]
By Stoichiometry of the reaction:
3 moles of oxygen gas is produced by 4 moles of [tex]KO_2[/tex]
So, 0.203 moles of oxygen gas is produced by = [tex]\frac{4}{3}\times 0.203=0.271mol[/tex] of [tex]KO_2[/tex]
Now, calculating the mass of [tex]KO_2[/tex] by using equation 1, we get:
Molar mass of [tex]KO_2[/tex] = 71.1 g/mol
Moles of [tex]KO_2[/tex] = 0.271 moles
Putting values in equation 1, we get:
[tex]0.271mol=\frac{\text{Mass of }KO_2}{71.1g/mol}\\\\\text{Mass of }KO_2=(0.271mol\times 71.1g/mol)=19.3g[/tex]
Hence, the mass of [tex]KO_2[/tex] needed is 19.3 grams.
The two most reactive families of elements are the halogens and the alkali metals. how do they differ in their reactivities?
How many different 3d states does the hydrogen atom have?
Different 3d states that does the hydrogen atom have are 10.
What are energy states of atom?The energy state is also familiarly known as the energy level plays a vital role in explaining the atomic structure. The energy levels or the energy state is any discrete (definite) value from a set of values of total energy for a subatomic particle confined by a force to limited space or for a system of such particles, for example like an atom or a nucleus.
The energy level is an old name used with the electron orbits of the Bohr model before quantum mechanics. In the quantum mechanical treatment and because of the uncertainty principle, thus we can not have orbits and hence the term energy states are used instead, thus technically there is not much of a difference between energy levels and energy states.
An electron in a hydrogen atom would have 10 states for a 3d orbital, like any other element.
n = 3, l = 2, in one of ml = 2, 1, 0, -1, -2 each with ms = -½ or +½ or a total of 10 possible states.
None of these are a ground state of an electron in the hydrogen atom.
Therefore, Different 3d states that does the hydrogen atom have are 10.
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Potassium forms an oxide containing 1 oxygen atom for every 2 atoms of potassium. what is the coefficient of oxygen in the balanced equation for the reaction of potassium with oxygen to form this oxide?
Final answer:
The balanced equation for the reaction of potassium with oxygen to form potassium oxide is 4 K(s) + O2(g) → 2 K2O(s), so the coefficient of oxygen (O2) is 1.
Explanation:
The student is asking about the reaction of potassium with oxygen to form potassium oxide, which contains 1 oxygen atom for every 2 atoms of potassium. To balance the chemical equation for this reaction, it is important to recognize that oxygen is diatomic (O2) and potassium forms an oxide where potassium has a 1+ charge, and oxide has a 2- charge. The formula for potassium oxide using the crisscross method becomes K2O.
The balanced equation for the reaction will be:
4 K(s) + O2(g) → 2 K2O(s)
Thus, the coefficient of oxygen (O2) in the balanced equation is 1.
Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions: ,
V+5
,
Cl−
,
O−2
A 10% glucose solution is placed in a dialysis tubing bag. the dialysis tubing bag is placed in a beaker that contains a 5% glucose solution. where is the highest concentration of water found?
Final answer:
Water moves from high to low concentration in osmosis; in this setup, the highest water concentration is in the beaker with 5% glucose solution.
Explanation:
Water moves from areas of high concentration to low concentration in osmosis, seeking equilibrium.
In the scenario provided, the highest concentration of water would be in the beaker containing the 5% glucose solution.
This movement occurs because the 10% glucose solution inside the dialysis tubing bag has a lower water concentration compared to the 5% glucose solution outside the bag.
Tina conducted an experiment to test her hypothesis. Her hypothesis was that by crushing aspirin and putting it into potting soil increases the growth rate of tomato plants. The results of the experiment show that there was no significant difference in the growth rates between the control and the experimental groups. What should Tina do with the results of this experiment?
explain the idea that the greek philosopher democritus proposed
Democritus, a Greek philosopher, proposed the idea of atomos or atomon - tiny, indivisible, solid objects - as the building blocks of all matter in the universe. His atomic theory challenged the prevailing belief of the time and laid the foundation for modern understanding of matter.
Explanation:About 2,500 years ago, Democritus, a Greek philosopher, proposed the idea that all matter in the universe is made up of tiny, indivisible, solid units called atomos or atomon. He believed that these atoms were the building blocks of all substances and that they cannot be further divided. This theory challenged the prevailing belief of the time that the universe was a single, unchangeable entity. Democritus' atomic theory laid the foundation for modern understanding of matter and influenced later scientists such as John Dalton and Albert Einstein.
Calculate the total pressure (in atm) of a mixture of .0200 mol of helium and .0100 mol of hydrogen in a 2.5 l flask at 10c
Zinc reacts with hydrochloric acid according to this reaction: Zn(s) + 2HCl (aq) → ZnCl2(aq) + H2(g) Which of the following will react the fastest? a. 2.0 gram lump of zinc in 0.10 M hydrochloric acid b. 2.0 gram sample of powdered zinc in 0.10 M hydrochloric acid c. 2.0 gram lump of zinc in 0.50 M hydrochloric acid d. 2.0 gram sample of powdered zinc in 0.50 M hydrochloric acid
Final answer:
The fastest reaction will be option d: a 2.0 gram sample of powdered zinc in 0.50 M hydrochloric acid, due to the greater surface area of the powdered zinc and the higher concentration of the acid.
Explanation:
When zinc metal is submerged into aqueous hydrochloric acid, a chemical reaction occurs that produces zinc chloride and hydrogen gas. The balanced equation for this reaction is:
Zn(s) + 2HCl(aq) → H₂(g) + ZnCl₂(aq)
This reaction is faster when the surface area of the zinc is increased and the concentration of hydrochloric acid is higher. Thus, option d, a 2.0 gram sample of powdered zinc in 0.50 M hydrochloric acid, will react the fastest because the powdered form of zinc has a larger surface area than a lump, allowing more acid to react with it at the same time. Additionally, a higher concentration of hydrochloric acid, such as 0.50 M compared to 0.10 M, will provide more acid particles in the solution to react with the zinc, thus speeding up the reaction.
1. Which processes are taking place in the system represented by the following equation?
2CO(g) + O2(g) →← 2CO2(g)
2. Consider the reaction represented by the equation 2HI(g) →← H2(g) + I2(g). At a temperature of 520 °C, the equilibrium concentration of HI is 0.80 M, of H2 is 0.010 M, and of I2 is 0.010 M. What is the K for the reaction?
The equilibrium constant indicates the ratio of product and reactant concentrations at equilibrium. The processes in the first equation involve the formation and decomposition of gases. The K value for the second equation is calculated using given equilibrium concentrations.
Explanation:The equilibrium constant (K) for a chemical reaction indicates the ratio of the concentrations of the products to the concentrations of the reactants at equilibrium. In the first equation, 2CO(g) + O2(g) → 2CO2(g), the forward reaction is the formation of CO2 from CO(g) and O2(g), while the reverse reaction is the decomposition of CO2(g) into CO(g) and O2(g).
To find the value of K for the reaction 2HI(g) → H2(g) + I2(g), we need to use the given equilibrium concentrations. Using the equation K = [H2][I2]/[HI]^2, we plug in the values to get K = (0.010)(0.010)/(0.80)^2 = 0.00015625.
Final answer:
The reaction represented by the equation 2CO(g) + O2(g) ↔ 2CO2(g) involves the formation and decomposition of carbon dioxide. The equilibrium constant (K) for the reaction 2HI(g) ↔ H2(g) + I2(g) at 520°C is 0.00015625.
Explanation:
The reaction represented by the equation 2CO(g) + O2(g) ↔ 2CO2(g) is an equilibrium reaction. It involves two processes: the formation of carbon dioxide from carbon monoxide and oxygen, and the reverse process where carbon dioxide decomposes to form carbon monoxide and oxygen.
At a temperature of 520°C, we are given the equilibrium concentrations of HI (0.80 M), H2 (0.010 M), and I2 (0.010 M). To find the equilibrium constant (K) for the reaction, we can use the formula:
K = [H2][I2]/[tex][HI]^2[/tex]
Substituting the given concentrations into the formula:
K = (0.010)(0.010)/[tex](0.80)^2[/tex] = 0.00015625
How many equivalents of pyruvate are needed to generate 1 equivalent of glucose?
When an aqueous solution of lead(ii) nitrate is mixed with an aqueous solution of sodium iodide, an aqueous solution of sodium nitrate and a yellow solid, lead iodide, are formed?
When an aqueous solution of lead(ii) nitrate (Pb(NO₃)₂) is mixed with an aqueous solution of sodium iodide (NaI), an aqueous solution of sodium nitrate (NaNO₃) and a yellow solid, lead iodide (PbI₂),
are formed.
The balanced equation for the reaction is:
Pb(NO₃)₂(aq)+2NaI(aq)→2NaNO₃(aq)+PbI₂(s)
If we dissolve 25 grams of salt in 251 grams of water, what is the mass of the resulting solution?
Rotting waste in landfills produces a gas that can be captured and used to generate electricity. what is this gas called?
Answer: The gas produced will be methane gas.
Explanation:
When waste is filled in the landfills, it gets rotten and it undergoes an aerobic decomposition (In the presence of oxygen), little methane gas is produced.
When the waste remains there, i less than a year, anaerobic conditions begin to generate (in the absence of oxygen) and methane-producing bacteria begin to decompose the waste and produces methane in a large amount.
This gas is also known as marsh gas and is considered as a greenhouse gas. This gas increases the temperature of the Earth's surface.
Hence, the gas produced will be methane gas.
A salt sample is placed into some water and nearly all of it dissolve without stirring and heating. the resulting solution is
Determine the number of atoms in 1.85 ml of mercury. (the density of mercury is 13.5 g/ml.)
To determine the number of atoms in 1.85 ml of mercury, convert the volume to mass using the density of mercury. Then, calculate the number of moles of mercury using its atomic mass. Finally, use Avogadro's number to calculate the number of atoms in the given amount of mercury.
Explanation:To determine the number of atoms in 1.85 ml of mercury, we need to convert the volume to mass using the density of mercury. The density of mercury is 13.5 g/ml. So, the mass of 1.85 ml of mercury is 1.85 ml x 13.5 g/ml = 24.975 g.
Next, we need to calculate the number of moles of mercury using its atomic mass. The atomic mass of mercury is 200.59 g/mol. To find the number of moles, we divide the mass (in grams) by the molar mass: 24.975 g / 200.59 g/mol = 0.1245 mol.
Finally, we can calculate the number of atoms in 0.1245 mol of mercury. Avogadro's number tells us that there are 6.022 x 10^23 atoms in 1 mol of any substance. So, the number of atoms in 0.1245 mol of mercury is 0.1245 mol x 6.022 x 10^23 atoms/mol = 7.49 x 10^22 atoms.
In a controlled experiment, the factor tested is called the A. constant. B. independent variable. C. dependent variable. D. control.
In a controlled experiment, the factor tested is called the [tex]\boxed{{\text{B}}{\text{. independent variable}}}[/tex].
Further Explanation:
A procedure that is performed in order to support, disprove or validate a hypothesis is known as an experiment. A hypothesis is an idea or thought that needs to be tested with the help of experiments.
Types of experiments:
1. Controlled experiments
The type of experiment that is used for comparing the results of experimental samples with the control samples is called a controlled experiment. Such experiments involve a drug trial. The experimental group will be the one that receives the drug and the other one receiving regular treatment will be the controlled group. The experimental group is also known as the treatment group. Another example of controlled experiments is the protein assay.
2. Natural experiments
These are also called quasi-experiments. These are performed by exposing individuals to the conditions that are governed by nature. Experiments involving weather changes and natural disasters are examples of natural experiments.
3. Field experiments
These are quite different from the experiments performed in the laboratory. Such experiments are usually performed in social studies. These have higher external validity as compared to normal lab experiments. Economic analysis of health and education are some examples of such experiments.
The variable that can be changed by the investigator is called the independent variable while the variable is the one that is affected by the changes in experimental conditions. All the variables in a controlled experiment are kept constant; except for the factor that is to be tested. Such a factor is called the independent variable or the experimental variable.
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Answer Details:
Grade: Senior School
Chapter: Keys to studying chemistry
Subject: Chemistry
Keywords: experiment, hypothesis, controlled experiment, natural experiment, field experiments, dependent variable, independent variable, quasi-experiments.
According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a compound, the mass of the compound is ____ the sum of the masses of the individual elements. select one:
The Law of conservation states that the mass of the chemical reactants and products cannot be formed or removed. Mass of compound is equal to the sum of individual mass.
What is the mass of conservation?The conservational mass is the law that expresses that the total mass of the compound containing the various elements will always be equal to the addition of the atomic mass of the individual elements.
This suggests that the mass of the reaction is not created by the addition of any other mass or destroyed by the elimination of any mass. So, the mass of the reactants will be like that of the mass of products.
Therefore, equal to the is correct blank.
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How much heat is released when 75 g of octane is burned completely if the enthalpy of combustion is -5,500 kJ/mol C8H18
Answer : The heat released during the reaction is [tex]-8.4\times 10^3kJ[/tex]
Explanation :
First we have to calculate the number of moles of octane [tex](C_8H_{18})[/tex].
[tex]\text{Moles of }C_8H_{18}=\frac{\text{Mass of }C_8H_{18}}{\text{Molar mass of }C_8H_{18}}[/tex]
Molar mass of [tex]C_8H_{18}[/tex] = 114 g/mole
[tex]\text{Moles of }C_8H_{18}=\frac{75g}{114g/mole}=0.658mole[/tex]
Now we have to calculate the heat released during the reaction.
[tex]\Delta H=\frac{q}{n}[/tex]
or,
[tex]q=\Delta H\times n[/tex]
where,
[tex]\Delta H[/tex] = enthalpy change = -5500 kJ/mol
q = heat released = ?
n = number of moles of [tex]C_8H_{18}[/tex] = 0.658 mol
Now put all the given values in the above formula, we get:
[tex]q=(-5500kJ/mol)\times (0.658mol)=-8358.66kJ=-8.4\times 10^3kJ[/tex]
Therefore, the heat released during the reaction is [tex]-8.4\times 10^3kJ[/tex]
The quantity of heat released when the octane is burned completely is -3,613.5 Joules.
Given the following data:
Mass of octane = 75 gramsEnthalpy of combustion = -5,500 kJ/molTo find the quantity of heat released when the octane is burned completely:
First of all, we would determine the number of moles of octane in this chemical reaction.
[tex]Number\;of\;moles \;(C_8H_{18})= \frac{Mass\; of\;octane}{Molar\;mass\;of\;octane}[/tex]
Substituting the values into the formula, we have;
[tex]Number\;of\;moles \;(C_8H_{18})= \frac{75}{114.23}[/tex]
Number of moles ([tex]C_8H_{18}[/tex]) = 0.657 moles.
Now, we can find the quantity of heat released when the octane is burned completely:
1 mole of octane = -5,500 kJ/mol
0.657 mole of octane = X kJ/mol
Cross-multiplying, we have:
[tex]X = -5500[/tex] × [tex]0.657[/tex]
X = -3,613.5 Joules.
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What are the signs of delta S, delta H and delta G for the formation of dew on a cool night? All the S ,H and G values are delta values, i'm just not going to write delta for each one.
a) +S, +H, +G
b) +S, +H, -G
c) +S, -H, +G
d) +S, -H, -G
e) -S, +H, +G
f) -S, +H, -G
g) -S, -H, +G
h) -S, -H, -G
pls help me, i'm so confused and this question has so many different options its overwhelmingg
The signs delta S, delta H and delta G for the formation of dew on a cool night are negative.
What is condensation reaction?Those reactions in which one product is formed by the combination of two molecules for example water vapors condenses into liquid dropltes is a condensation process.
Dew which is formed on a cool night is an exothermic reaction as in this reaction state changes from gaseous which have high kinetic energy to liquid so some amount of energy is released during this conversion.
For an exothermic reaction values are:
ΔH = -ve (as energy is lost in the form of heat)
ΔS = -ve (randomness decreases from gaseous state to liquid state)
ΔG = -ve (shows the spontaenity of the reaction)
Hence option (H) is correct.
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Why does ice float in liquid water? the high surface tension of liquid water keeps the ice on top. stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water. the crystalline lattice of ice causes it to be denser than liquid water. the ionic bonds between the molecules in ice prevent the ice from sinking?
Since the molecules can move wider apart due to the hydrogen bonds created when water freezes into ice, the ice floats in the water because it has a lower density overall.
What is surface tension of liquid?The attractive force that the molecules below a liquid's surface exert on its surface molecules tends to drag those molecules into the bulk of the liquid, giving the liquid the shape with the least amount of surface area.
When water turns to ice, the ice loses a lot of its water-like density and continues to float on the lake's surface.
Water loses density when it grows colder below 4° Celsius, forcing water that is about to freeze to float to the top.
Therefore, This occurs as a result of the water molecules losing energy and moving less than the temperature drops.
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