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2 years ago

How many atoms of Mg are present in 97.22 grams of Mg?

Chemistry

1 answer:

Lostsunrise [7]2 years ago

7 0

Answer: Option (b) is the correct answer.

Explanation:

It is given that mass of Mg is 97.22 g and it is known that molar mass of Mg is 24.305 g/mol.

So, calculate the number of moles as follows.

No. of moles = $\frac{mass given in grams}{Molar mass}$

= $\frac{97.22 g}{24.305 g/mol}$

= 4 mol

Also, it is known that 1 mole has $6.023 \times 10^{23}$ atoms/mol. Therefore, calculate the number of atoms in 4 mol as follows.

$4 mol \times 6.023 \times 10^{23} atoms/mol$

= $24.08 \times 10^{23}$ atoms

or, = $2.408 \times 10^{23}$ atoms

Thus, we can conclude that there are $2.408 \times 10^{23}$ atoms in 97.22 grams of Mg.

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Two students are given different samples of a substance and are instructed to determine the properties of the substance.

Hunter-Best [27]

The complete question is given below:

Two students are given different samples of a substance and are instructed to determine the properties of the substance.

Which statement describes a property that will be the same for both students?

A. color because it is an extensive property

B. mass because it is an extensive property

C. boiling point because it is an intensive property

D. volume because it is an intensive property .

ANSWER

The correct option is C.

The physical properties of substances are divided into two, intensive and extensive properties.

Intensive properties refers to those features of a substance that do not depend on the quantity of the material that is available. Whether the sample available is big or small, the intensive properties remain the same. Examples of intensive properties are: melting point, boiling point, refractive index, hardness, density color, etc. This question is asking us to look for an intensive property.

Extensive properties refers to those characteristics of a substance that depend on the amount of substance present. Examples of these properties are: mass, volume, size, weight, length, etc.

From the options given, option A is wrong because color is not an extensive property, it is intensive. Option B is wrong because the mass depend on the amount of sample given and the same thing apply to option D.

The correct option is C, because no matter the quantity of that substance that you have, the boiling point will always remains the same.

6 0

2 years ago

A student determines measures the mass of one mole of carbon and finds it to be 12.22 grams. if the accepted value is 12.11 gram

Gre4nikov [31]

Answer:-

0.91% is the students % of error

Explanation: -

Accepted value= 12.11 grams

Measured value = 12.22 grams

Error = 12.22-12.11 = 0.11 grams

Percentage error = $\frac{0.11 grams}{12.11 grams}$ x100

= 0.91 %

Thus 0.91% is the students % of error

5 0

2 years ago

According to the law of conservation of mass in a chemical reaction the total starting mass of all the reactants equals the tota

Ber [7]

I believe the correct answer true. According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equals the total final mass of all the products. This law states that mass cannot be created or be destroyed. So, the total mass that goes in a process should be equal to the mass that goes out the process. This is true for chemical reactions and physical processes. It is Antoine Lavoisier who described this and is a basic principle used in physics and in chemistry. Mass, unlike energy, cannot be transformed to any form so however the transformation happens the mass should be constant.

3 0

2 years ago

Select the correct answer. A student places a sample of white sodium bicarbonate powder in a test tube and heats it. The student

inessss [21]

Answer is: D. It is not sodium bicarbonate.

Balanced chemical reaction of heating sodium bicarbonate: 2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O.

This is chemical change (chemical reaction), because new substances are formed (sodium carbonate, carbon(IV) oxide and water), the atoms are rearranged, so there is no sodium bicarbonate (NaHCO₃) in the test tube.

8 0

2 years ago

A) How many moles of CO2 and H2O are formed from 3.85 mole of propane C3H8 (This calculation needs to be done twice-once fro CO2

4vir4ik [10]

Answer:

a) 11.55 moles of carbon dioxide gas are formed from 3.85 mole of propane.

15.4 moles of water are formed from 3.85 mole of propane.

b)0.5176 moles of water are formed from 0.647 mole of oxygen gas.

0.1294 moles of propane are consumed.

Explanation:

$C_3H_7+5O_2\rightarrow 3CO_2+4H_2O$

a) Moles of propane = 3.85 moles

According to reaction, 1 mole of propane gives 3 moles of carbon dioxide gas.

Then 3.85 moles of propane will give:

$\frac{3}{1}\times 3.85 mol=11.55 mol$ of carbon dioxide gas.

11.55 moles of carbon dioxide gas are formed from 3.85 mole of propane.

According to reaction, 1 mole of propane gives 4 moles of water gas.

Then 3.85 moles of propane will give:

$\frac{4}{1}\times 3.85 mol=15.4 mol$ of water .

15.4 moles of water are formed from 3.85 mole of propane.

b) Moles of oxygen gas = 0.647 moles

According to reaction, 5 mole of oxygen gas gives 4 moles of water.

Then 0.647 moles of oxygen will give:

$\frac{4}{5}\times 0.647 mol=0.5176 mol$ of water.

0.5176 moles of water are formed from 0.647 mole of oxygen gas.

According to reaction, 5 mole of oxygen gas reacts with 1 mole of propane.

Then 0.647 moles of oxygen will give:

$\frac{1}{5}\times 0.647 mol=0.1294 mol$ of propane.

0.1294 moles of propane are consumed.

5 0

2 years ago