Question

plz solve and answer all these questions
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Answer 1

Answer:

According to the table an average atom of sodium is 23/12 = 1.9 times as massive as an average atom of carbon. Thus, in order to have the same number of atoms of sodium we need a mass of carbon that is 23/12 times its mass. Since we have 12 g of carbon, we have 23/12 x 12 = 23 g sodium.

Answer 2

Answer:

Chemistry

Explanation:

1) 12 grams of carbon is not one mole unless you specifically mean C-12 isotope.

However the molar mass of the weighted average of the isotopes, which is the relative atomic mass (or atomic weight) is 12.01, which is close enough here.

So lets call 12 grams one mole. So it will contain the Avogadro number of atoms, which is 6.022 x 10^23 atoms.

One mole of sodium contains the avogadro

number also.

Therefore the answer is 22.989769 grams

22.99 (to 4 sig. figs).

2) Given: 42 g of N2

Solve for O2 mass that contains the same number of molecules to 42 g of N2.

Solve for the number of moles in 42 g of N2

1 mole of N2 = (14 × 2) g = 28 g so the number of moles in 42 g of N2 is equal to 42 g / 28 g per mole = 1.5 moles

Solve for mass of 1 mole of oxygen

1 mole of O2 = 16 g × 2 = 32 g per mole

Solve for the mass of 1.5 moles of oxygen

mass of 1.5 moles of O2 = 32 g per mole × 1.5 moles

mass of 1.5 moles of O2 = 48 g

So 48 g of O2 contains the same number of molecules as 42 g of N2.

3) 1 MOLE of hydrogen atoms will weigh 1.008 grams. That said, to find the mass of one ATOM, we need to convert from moles to atoms as follows: 1.008 grams/mole Hydrogen × (1 mole/6.022x1023 atoms) = 1.67 x 10-24 grams.

4) a) You can just count it

b) Air is not supposed to be considered as a pure substance. Because air is a mixture of different gases. - Air mostly contains nitrogen and oxygen in about 78% and 20% respectively.

c) There is no chemical formula for air as it is a mixture of many compounds. The major components would be Nitrogen (N2), Oxygen (O2), Carbon Dioxide (CO2), Water (H2O), and many others in minute amounts. Nitrogen makes up 78.1% of air, while oxygen makes up 20.9% of air.

d) Sorry, can't answer this

e) The most abundant naturally occurring gas is Nitrogen (N2), which makes up about 78% of air. Oxygen (O2) is the second most abundant gas at about 21%.

5)

$m h_{2}o = 18g$

$mr h_{2} = \frac{18g}{mol}$

$n h_{2}o = \frac{m}{mr} = \frac{18}{18} = 1 \: mol$

1 mol of anything has roughly

$6.02 \times {10}^{23}$

atom/molecule of that thing.

This means that 18 g of H 2 O has

$6.02 \times {10}^{23}$

H 2 O molecules.

Since each H 2 O molecules have 2 hydrogen atoms, there are a total of

$1.204 \times {10}^{24}$

hydrogen atoms

6) It is equal to Avogadro’s number (NA), namely 6.022 × 1023. If we have one mole of water, then we that it will have a mass of 2 grams (for 2 moles of H-atoms) + 16 grams (for one mole O atom), which finally result to 18 grams.