Chemistry

1In the balanced equation N₂ + 3H₂ → 2NH₃, how many moles of hydrogen react with 2 mol of nitrogen?

2The empirical formula of C₆H₁₂O₆ is

3In 2H₂ + O₂ → 2H₂O, the mole ratio of H₂ to O₂ is

4Balance: N₂ + H₂ → NH₃. The coefficients are

5The formula of calcium carbonate is

6A compound contains 80% carbon and 20% hydrogen by mass. What is its empirical formula? (C = 12, H = 1)

7Balance: Al + O₂ → Al₂O₃. The coefficients are

8A compound has empirical formula CH₂ and relative molecular mass 56. Its molecular formula is

9A hydrated salt CuSO₄·xH₂O loses 36% of its mass on heating. Find x (CuSO₄ = 160, H₂O = 18).

10CH₄ + 2O₂ → CO₂ + 2H₂O. How many moles of oxygen are needed to burn 3 mol of methane completely?