Question

What is mass of water formed when 4 grand hydrogen and 64 grams of oxygen gas combined together

Answer 1

Answer:

So 2 g of Oxygen will combine with 2/8 or 0.25 g of hydrogen to produce 2.25 g of water and 2 — 0.25 = 1.75 hydrogen will remain unreacted . 1 g H2 reacts with= 8 g Oxygen. So 64 g of oxygen reacts with= 8 g H2. So (64+8)=72 g of water will be formed

Answer 2

Answer:

Mass of water formed when 4 g hydrogen and 64 g of oxygen are combined together is 72 g.

Explanation:

The balanced chemical equation for the formation of water is:

$2H_{2} +O_{2}$ → $2H_{2} O$

Given mass of hydrogen = 4 g

Molar mass of hydrogen = 1 g/mol

Number of moles = given mass ÷ molar mass

                             = $\frac{4}{1}$

                             = 4 moles

Given mass of oxygen = 64 g

Molar mass of oxygen = 32 g/mol

Number of moles = given mass ÷ molar mass

                             = $\frac{64}{32}$

                             = 2 moles

Hydrogen and oxygen are combined in the ratio 2:1.

For 2 moles of $H_{2}$ , 2 moles of $H_{2} O$ is produced.

∴4 moles of $H_{2}$ gives 4 moles of $H_{2} O$

Number of moles = given mass ÷ molar mass

Molar mass of $H_{2} O$ = 18 g/mol

∴Mass of $H_{2} O$ produced = 4 × 18

                                        = 72 g