Answer:
He should not have reached over the burner while it was on. he should have shut it off first.
Explanation:
Final answer:
Xander's primary error was safety-related by reaching over an ignited Bunsen burner, risking burns or fire. Additionally, promptly reporting the dropped test tube was correct but underscores the need for immediate action when accidents occur. Cleaning up at the end demonstrated proper protocol adherence.
Explanation:
The error made by Xander in the laboratory scenario involves a breach in safety protocol while working with a Bunsen burner. When he reached over the burner to get his chemicals, he exposed his arms or potentially loose clothing to the flame, creating a risk of burns or catching fire. This action is against standard laboratory safety rules, which dictate that individuals should keep all body parts and flammable materials away from open flames to prevent accidents.
Additionally, after dropping a test tube, he should have practiced proper spill protocol, which includes notifying the teacher immediately, not just at the end of the lab session. Although he did this correctly, it is also important to note that all incidents and accidents should be reported promptly to prevent any hazardous conditions from persisting.
Lastly, it's essential to maintain cleanliness in the lab by promptly cleaning up any spilled materials and disinfecting the workspace, along with ensuring the proper shutdown of the burner and sealing of chemical containers at the end of the practical. Xander's final act of cleaning up his area aligned with correct laboratory procedures.
Which statement best describes the function of enzymes?
Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells. They are vital for life and serve a wide range of important functions in the body, such as aiding in digestion and metabolism.
Enzymes lower the activation energy level of a chemical reaction, thus making it so the reaction will proceed.
What are enzymes?Enzymes are proteins that help speed up chemical reactions in our bodies.
Enzymes are proteins that speed up the rate of a chemical reaction without being used up during the reaction.
They are biological catalysts. Catalysts, as we know lower the activation energy for reactions and speed them up.
The lower the activation energy for a reaction, the faster the rate.
Thus enzymes speed up reactions by lowering the activation energy.
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An atom with 4 protons, 5 neutrons, and 4 electrons has an atomic mass of _____ amu.
(place a whole number)
Answer:
9
Explanation:
atomic mass = number of protons + number of neutrons = 4+5 = 9 amu
Answer:
9
Explanation:
5 neutrons + 4 electrons = 9. We don't use protons in the calculation because the mass is so small that it can be ignored. Good luck ◕‿◕
Which of the following correctly describes the importance of the nitrogen cycle?
Are there any answer choices? If not, here are some possible responses you may see (that are correct, of course):
*It is used in the process of decomposition.
*It is used to release ammonia from dead animals that ultimately gets turned into nitrogen-based substances.
*It involves the formation of nitrates into nitrogen to complete the nitrogen cycle.
I hope I helped!
If you find the answer choices, just comment them down below and I will gladly tell you which one is correct. :)
Why is the melting of ice a physical change ?
Answer:
Because No New Substance if Formed!
Explanation:
When ice melts, it is still considered to be water, it's just no longer a solid. The molecules of water do not become something else and simply just change phases. A chemical reaction requires that a new substance be formed, for example when you burn paper, a new substance is formed. Also melting ice is reversible, you can just freeze it again, while chemical reactions cannot be reversed!
Which is true of chemicals?
A. Things containing chemicals always cost a lot of money.
B. Chemicals are never dangerous.
c. Chemicals are in many substances in a home.
D. Chemicals are rarely found on Earth.
Answer:
C
Explanation:
your cleaning items have chemicals batteries have chemicals.
Chemicals are in many substances in a home.
What is Chemicals?We all are made of chemicals and everything around us is made of chemicals. Everything we hear, see, smell, taste, and touch involve chemistry and chemicals (matter). Hearing, seeing, tasting, and touching all involve intricate series of chemical reactions and interactions in our body. Many of the changes we observe in the world around are caused by chemical reactions. Chemistry is not limited to beakers and laboratories. It is all around us, and the better we know chemistry, the better we know our world.Which statement are true for Chemicals?(c) Chemicals are in many substance in home is the true statement
It can be explained by an example
A coffee we use in home contains chemicals such as
Acetaldehyde , Tannin , Thiamin
these all are the chemicals used in coffee beans.
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Consider the following system at equilibrium.
CaCO3(s) = Ca2+(aq) + CO32-(aq)
The addition of which compound will cause a shift in equilibrium because of a common ion effect?
OCCIA
CO2
CuSO4
Na2CO3
Answer:
Na₂CO₃.
Explanation:
Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.The compound that has a common ion effect is Na₂CO₃.
When it is added to the solution, it is dissolved to produce Na⁺ and CO₃²⁻ which increases the concentration of CO₃²⁻ that will increase the concentration of the products side, so the reaction will be shifted to the left side to suppress the increase in the concentration of CO₃²⁻.
Answer:
D. eez Nutz
Explanation:
Na2Co3
What is the chemical formula for zinc phosphate?
ZnZP2
Zn(PO)
Zn3(PO.),
Zn(NO3)2
Zn₃(PO₄)₂ is the chemical formula for zinc phosphate.
What is a chemical formula?The chemical formula of a compound means the symbolic representation of the composition of a compound.
Zn₃(PO₄)₂ is the chemical formula for zinc phosphate.
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A chemist runs a reaction and has a percent yield of only 30%. Which of the following would NOT explain the low percent yield?
The reaction was stopped too soon, and some of the reactant had not yet been converted to product.
One of the products was a gas that was not contained and weighed.
The product still had moisture in it when the mass was recorded.
Some of the product was spilled before the mass was recorded.
Answer:
the moisture
Explanation:
A low percent yield indicates less product formed than expected. Moisture in the product would not cause a low yield but an inaccurately high yield if anything. The correct percent yield calculation requires a pure product and accounts for less than perfect recovery due to various physical and chemical losses.
Explanation:When a chemist runs a reaction and obtains a percent yield of only 30%, it indicates that there was less product formed than the calculated theoretical yield. Various factors can contribute to a low percent yield, including experimental errors, incomplete reactions, and losses due to product recovery issues. The options given all indicate potential reasons for a low percent yield except for the option where the product still had moisture in it when the mass was recorded. If the product was weighed with moisture, that would generally result in a higher mass and potentially a percent yield greater than 100%, not lower. So, this would not be a reason for a low percent yield, but rather for an inaccurately high yield.
Many reactions, especially on a laboratory scale, will not achieve a 100% yield due to the law of conservation of mass. Even in industry, achieving yields close to 100% is challenging. The chemist must always take care to purify the products to obtain as accurate a percent yield as possible, reflecting the amount of desired product actually formed compared to the theoretical prediction. The percent yield is calculated using the formula: (actual yield / theoretical yield) x 100%.
urgent!!
Darla claims that the first periodic table developed by Mendeleev was not completely accurate, so it is not useful at all. Harmony argues that it helped establish the periodic table we use today, making it more credible. Who is correct and why?
Darla is correct, because a model that has any mistakes should be thrown out.
Darla is correct, because a good model would not need to change.
Harmony is correct, because Mendeleev’s model had all of the information correct in the first version.
Harmony is correct, because Mendeleev’s model made predictions that came true.
Answer:
Harmony is correct, because Mendeleev’s model made predictions that came true.
Explanation:
Mendeleev published periodic table.
Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he did some other things that made his table much more successful.
Our answer is : Harmony is correct, because Mendeleev’s model made predictions that came true.
Answer:
Harmony is correct, because Mendeleev’s model made predictions that came true.
Explanation:
what is The most common form of matter in the universe
Hello! My name is Zalgo and I am here to help you out today. The most common form of matter in the universe would be "Plasma". Plasma is gas that is heated a lot so it turns into high energy (high energy would be said "Plasma").
I hope that this helps! :D
"Stay Brainly and stay proud!" - Zalgo
(By the way, do you think you could mark me as Brainliest? I'd greatly appreciate it! Thanks XP)
What area of study in chemistry is concerned with the heat transfers that occur during chemical reactions?
Answer:
Thermochemistry
Explanation:
Thermochemistry is the area of study in chemistry that is concerned with the heat transfers that occur during chemical reactions.
Working with SI (metric) Units
For each of the following commonly used measurements, indicate its symbol.
liter
gram
milliliter
kilogram
meter
centigram
milligram
centimeter
kilometer
second
millimeter
milliseconds
The symbols for commonly used metric measurements include L for liter, g for gram, mL for milliliter, kg for kilogram, m for meter, and cm for centimeter.
Explanation:The symbol for liter is L.
The symbol for gram is g.
The symbol for milliliter is mL.
The symbol for kilogram is kg.
The symbol for meter is m.
The symbol for centigram is cg.
The symbol for milligram is mg.
The symbol for centimeter is cm.
The symbol for kilometer is km.
The symbol for second is s.
The symbol for millisecond is ms.
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3. How many kJ of heat are required to raise the temperature of 100.0 g of water from 25.0 c to 75.0 c? The specific heat of water is 4.184 J/g-c.
Answer:
20.9 kJ.
Explanation:
We can calculate the amount of heat (Q) released to water using the relation:Q = m.c.ΔT,
where, Q is the amount of heat released to water (Q = ??? J).
m is the mass of water (m = 100.0 g).
c is the specific heat capacity of solution (c = 4.18 J/g.°C).
ΔT is the difference in T (ΔT = final temperature - initial temperature = 75.0°C - 25.0°C = 50.0°C).
∴ Q = m.c.ΔT = (100.0 g)(4.18 J/g.°C)(50.0°C) = 20900 J = 20.9 kJ.
In carbon monoxide, there is always 1.33 g of oxygen for every
1g of carbon. How many grams of carbon are in a 16.03 g
sample of carbon monoxide? ______g carbon
There are 6.88 g of carbon in 16.03 g sample of carbon monoxide.
Carbon monoxide has formula as CO.
C => carbon
O => oxygen
From the question given above, we were told that there is always 1.33 g of oxygen for every 1 g of carbon. Thus,
O = 1.33C ............. (1)
We were also told that the mass of CO is 16.03 g i.e
C + O = 16.03 ........... (2)
Summary:O = 1.33C ............. (1)
C + O = 16.03 ........... (2)
From the equation above, we can obtained the mass of Carbon (C) as follow:
C + O = 16.03
O = 1.33C
C + 1.33C = 16.03
2.33C = 16.03
Divide both side by 2.33
C = 16.03 / 2.33
C = 6.88 g
Therefore, 16.03 g of the sample of carbon monoxide contains 6.88 g of carbon.
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Diamond, graphite, and fullerenes share what property? A. They are all made of carbon (C) bonded to a metal. B. Their shape. C. They are all made of carbon (C). D. They are all good conductors.
Answer:
They are all made of carbon
Explanation:
Diamond, graphite, and fullerenes are all made of carbon.
Hope this helps!
Diamond, graphite, and fullerenes "Are all made of carbon".
What is a Diamond?The crystal structure known as diamond cubic would be used to describe the solid form of something like the element carbon known as diamond.
What are fullerenes?
Due to its resemblance to the appearance of a soccer ball, fullerenes with a spherical shape are frequently described as "buckyballs" or Buckminster fullerenes.
Therefore, the correct answer is an option (A)
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Which of the following pressures is equal to 760 mm Hg? 2.0 atm 101.3 Pa 101,300 kPa 101,300 Pa
Answer:
101,300 kPa.
Explanation:
It is known that:
760 mm Hg = 101,300 kPa.
760 mm Hg = 1.0 atm.
So, the right choice is: 101,300 kPa.
When magnesium chloride reacts with water, 5.85 L HCl(g) is produced.
molar mass of HCl = 36.5 g/mol
molar mass of MgCl2 = 95.2 g/mol
How many moles of HCl was produced?
How many moles of MgCl2 reacted?
What mass of MgCl2 reacted?
Answer: How many moles of HCl was produced?
⇒ 0.261 moles of HCl
How many moles of MgCl2 reacted?
⇒ 0.131 moles of MgCl2
What mass of MgCl2 reacted?
⇒ 12.4 g MgCl2
Explanation:
i just did it
Answer: (i) 0.261 moles of HCl, (ii) 0.131 moles of [tex]MgCl_2[/tex] and (iii) 12.5 grams of [tex]MgCl_2[/tex]
Explanation: The balanced equation for the formation of HCl by the reaction magnesium chloride with water is:
[tex]MgCl_2+2H_2O\rightarrow 2HCl+Mg(OH)_2[/tex]
From above balanced equation, there is 1:2 mol ratio between magnesium chloride and HCl.
As per the given information, 5.85 L of HCl gas is produced. here, temperature and pressure is not mentioned, so let's assume STP conditions.
At STP, volume of 1 mol of a gas is 22.4 L. With the help of this, we can calculate the moles of HCl present in 5.85 L.
[tex]5.85LHCl(\frac{1mol}{22.4L})[/tex]
= 0.261 mol HCl
As there is 1:2 mol ratio between magnesium chloride and HCl, we can calculate the moles of magnesium chloride from the above calculated moles of HCl as:
[tex]0.261molHCl(\frac{1molMgCl_2}{2molHCl})[/tex]
= 0.131 mol [tex]MgCl_2[/tex]
Molar mass of magnesium chloride is given as 95.2 gram per mol. On multiplying the moles by molar mass we can calculate its mass reacted.
[tex]0.131molMgCl_2(\frac{95.2g}{1mol})[/tex]
= 12.5 g [tex]MgCl_2[/tex]
What would be the original temperature of a gas that has a volume of 2.0 L and a pressure of 2.0 ATM and an unknown temperature that the volume increased to 3.5 L in its pressure decreased to 1.0 ATM if the final temperature is measured to be 11°C
Answer:
= 51.57 °C
Explanation:
The combined gas equation shows that P₁V₁/T₁=P₂V₂/T₂ where P represents pressure, V represents volume and T absolute temperature
From the information provided in the question,
Since we are finding the initial or original temperature, we can make T₁ the subject of the formula.
T₁=P₁V₁T₂/P₂V₂
P₁=2.0 ATM
P₂= 1.0 ATM
V₁=2.0 L
V₂= 3.5 L
T₁=?
T₂= (11+273) K=284 K
Using these values in the formula:
T₁= (2.0 ATM × 2.0 L× 284 K)/(1.0 ATM × 3.5 L)
=324.57 K
324.57-273= 51.57 °C
What statement correctly describes protons?
Answer:
A positively charged subatomic particle
Adam wants to work in the field of forensic science and follow the rules for handling evidence. Which organization can he join to fulfill this aspiration?
International Academy of Forensic Science
National Academy of Sciences
National Academy of Forensic Science
National Science Academy
Answer:
I would say its c . National Academy of Forensic Science
Explanation:
I would say its c . National Academy of Forensic Science
Answer:
National Academy of Forensic Science
Explanation:
Science with forensic application is a branch of scientific disciplines that allows them to help the police and justice to determine the circumstances in the commission of an infraction and allow the identification of the perpetrators. Criminalistics applies knowledge, methods and techniques for the examination of material related to a criminal act to determine, and administer justice.
Why does the rate of most reactions decrease over time?
A decrease in reactant concentration reduces the frequency of successful collisions.
A decrease in temperature reduces the average kinetic energy of the particles.
An increase in product concentration interferes with the effectiveness of the catalyst.
An increase in pressure of the system reduces the movement and energy of particles.
Answer:
A decrease in reactant concentration reduces the frequency of successful collisions.
Explanation:
The rate of any chemical reaction is the change in the concentration of the reactants with time.Rate = - d[Reactants]/d(time).
Also, the rate of a chemical reaction can be given by:Rate = k[Reactants]ˣ,
where, k is the rate constant of the reaction.
x is the no. of moles that the rate of the reaction depends on.
So, it is clear that the rate of the reaction is directly proportional to the concentration of the reactants.
The concentration of the reactants is at its maximum value at the time of the start of the reaction "mix up", so, the rate of the reaction is maximum at the start of the reaction.So, the rate of most reactions decrease over time due to there is a decrease in the concentration of the reactants with time and so, the chance for collision of the reactants decrease.So, the right choice is:
A decrease in reactant concentration reduces the frequency of successful collisions.
20 grams of water. She poured out 15 grams. Which of the following physical properties of the water changes?
A .Boiling point
B. Density
C .Electrical conductivity
D .Volume
Answer:
Volume only intrinsic
Explanation:
A chemist requires 6.00 liters of 0.320 M H2SO4 solution. How many grams of H2SO4 should the chemist dissolve in water?
121 grams
159 grams
176 grams
188 grams
Answer:
188 grams
Explanation:
molarity = moles per litre
0.320 moles=1 litre
number of moles in 6 litres = (0.320×6)÷1
=1.92 moles
mass=moles ×relative molecular mass
1.92×(2+32+64)= 188
answers= 188 grams
Answer:
The correct answer is 188 grams
The chemist should dissolve 188 grams of H2SO4 in water.
Further Explanation
Molarity is the concentration of a solution in moles per liter. It is calculated by dividing the number of moles of a solution, n by its volume in liters, V. That is; Molarity = n/V
When given the molarity of a solution and the volume of the solution then we can get the number of moles, by multiplying the molarity by volume; n = MV.
The number of moles of a compound or an element can also be calculated by dividing the mass of the compound by its relative molecular mass.
In this case, we are given; volume = 6.00 L and Molarity = 0.320 M
Therefore, we can calculate the number of moles by multiplying volume and molarity.
Number of moles = 6.0 L × 0.320 M
= 1.92 moles
Relative molecular mass of H2SO4 is 98.079 g/mol
Mass of the solution = moles × relative molecular mass
= 1.92 moles × 98.079 g/mol
= 188.312 g
≈ 188 g
Learn more about Molarity; https://brainly.in/question/1159016 Molarity, moles and volume conversions; https://brainly.com/question/12834126Answer detailsGrade: High school
Subject: Chemistry
Chapter: Stoichiometry
Keywords: Molarity, moles, molecular mass and volume.
WILL MARK BRAINLIEST
How many electrons can be held in the energy level n = 4?
Answer:
32
Explanation:
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons.
What is the solution to the problem expressed to the correct number of significant figures? (102,900 ÷ 12) + (170 × 1.27) = ? A. 8,790 B. 8,790.9 C. 8,791 D. 8,800
Answer:
The correct answer is option B.
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
(102,900 ÷ 12) + (170 × 1.27)
= (8575)+ (215.9)
= 8790.9
There are 5 significant figures in 8790.9 which are ,'8','7','9','0' and '9'.
To solve the problem expressed to the correct number of significant figures, follow the rules for addition/subtraction and multiplication/division of significant figures.
Explanation:To solve the problem expressed to the correct number of significant figures, we need to follow the rules for significant figures:
Addition or subtraction: The final answer should have the same number of decimal places as the number with the fewest decimal places. In this case, (102,900 ÷ 12) has no decimal places and (170 × 1.27) has two decimal places. Therefore, the final answer should have two decimal places.Multiplication or division: The final answer should have the same number of significant figures as the number with the fewest significant figures. In this case, (102,900 ÷ 12) has five significant figures and (170 × 1.27) has three significant figures. Therefore, the final answer should have three significant figures.Using these rules, the solution to the problem expressed to the correct number of significant figures is 8,791 (option C).
Ice floats on water,but an iron nail sinks.
Answer:
True
Explanation:
Ice floats on water, for water is more dense than ice, allowing water to "support" the ice on top.
Iron nail, on the other hand, is more dense than water, allowing the nail to sink.
Answer: True an iron nail is more dense than the water and Ice the ice is less dense than the water making it float. Hopes this helps :)
An object was measured by a worker as
17.4cm long, however, the manufacturer
specifications list the length of the object at
17.9cm. What is the percent error in the
workers measurement?
Answer:
[tex]\boxed{2.8 \, \%}[/tex]
Explanation:
[tex]\text{Percent error} = \dfrac{\lvert \text{Measured - Actual}\lvert}{ \text{Actual}} \times100 \, \%[/tex]
Data:
Predicted = 17.4 cm
Actual = 17.9 cm
Calculation:
[tex]\text{Percent error} = \dfrac{\lvert 17.4 - 17.9\lvert}{17.9} \times 100 \, \% \\\\= \dfrac{\lvert-0.5\lvert}{17.9} \times 100 \, \% = \dfrac{0.5}{17.9} \times 100 \, \% \\\\= 0.028 \times 100 \, \% = \textbf{2.8 \%}\\\\\text{The percent error in the measurement is } \boxed{\textbf{2.8 \%}}[/tex]
Calculate the mass percent composition of carbon in C3H10N4O4. Enter your answer as a number to 1
decimal place.
Answer:
Explanation:
I'm using approximate molecular masses.
3 * C = 3 * 12 = 36
10*H = 10* 1 = 10
4*N = 4 *14 = 56
4*O = 4 * 16 = 64
================
Total = 166
Molecular Mass = 166
% Carbon = 36/166 * 100 = 21.7
Carbon = 21.7%
My atomic masses are approximate because all periodic tables are different. Re do the problem using the numbers off your periodic table.
What would happen to a weak base dissociation equilibrium if more products
were added?
A. The equilibrium constant would shift to a new constant
O
B. The concentration of reactants would increase.
O
C. The equilibrium concentrations would stay the same,
D. The concentration of products would increase
When more products are added to a weak base dissociation equilibrium, the equilibrium will shift to the left, favoring the reactants and causing the concentration of products to increase.
Explanation:When more products are added to a weak base dissociation equilibrium, the equilibrium will shift to the left, favoring the reactants. This is because the introduction of more products will cause the reaction to use up some of the reactants to form more products, in order to reach a new equilibrium. Therefore, the concentration of products would increase, and the concentration of reactants would decrease.
Final answer:
When more products are added to a weak base dissociation equilibrium, the concentration of products would increase.
Explanation:
When more products are added to a weak base dissociation equilibrium, the equilibrium will shift to favor the reactants, resulting in an increase in the concentration of products. This is in accordance with Le Chatelier's Principle, which states that a system at equilibrium will adjust to counteract any changes imposed on it. Therefore, the correct answer is option D: The concentration of products would increase.
not sure how to write this question so I will add an image
Answer:
2H3PO4 + 3Ca(OH)2 = Ca3(PO4)2 + 6H2O
3CaO + P2O5 = Ca3(PO4)2
Explanation:
1) When phosphoric acid reacts with calcium hydroxide neutralization reaction takes place in which calcium phosphate is formed along with formation of water.
The balanced chemical equation is give as:
[tex]2H_3PO_4+3Ca(OH)_2\rightarrow Ca_3(PO_4)_2+6H_2O[/tex]
2) When calcium oxide acid reacts with phosphorus pentoxide addition reaction takes place in which calcium phosphate is formed.
The balanced chemical equation is give as:
[tex]3CaO+P_2O_5\rightarrow Ca_3(PO_4)_2[/tex]