85.7k views
1 vote
Which gas contains the same number of molecules as 9g of water?

A) 2g of hydrogen
B) 14g of nitrogen
C) 32g of oxygen
D) 44g of carbon dioxide​

1 Answer

3 votes

Answer:

B) 14g of nitrogen

Step-by-step explanation:

To calculate number of molecules in 9g of water, we first convert mass to mole by using mole = mass/molar mass i.e.

mole = 9g/18g/mol of water

mole = 0.5mol

Next, we multiply by 6.022 × 10^23 molecules to get 3.011 × 10^23 molecules in 9g of water (H2O).

- For hydrogen gas: Molar Mass = 2g/mol, mass = 2g

mole = 2/2 = 1

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

- For Nitrogen gas: Molar Mass = 28g/mol, mass = 14g

mole = 14/28 = 0.5mol

No. of molecules = 0.5 × 6.022 × 10^23 = 3.011 × 10^23 molecules.

- For Oxygen gas: Molar Mass = 32g/mol, mass = 32g

mole = 32/32 = 1mol

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

- For carbondioxide gas: Molar Mass = 44g/mol, mass = 44g

mole = 44/44 = 1mol

No. of molecules = 1 × 6.022 × 10^23 = 6.022 × 10^23 molecules.

Based on he results of each calculation, NITROGEN contains the same number of molecules as 9g of water

User Joozek
by
7.2k points