Molecules can be dissolved? Why?

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same

Read the chemical equation. 2c2h2 + 5o2 → 4co2 + 2h2o which of the following statements would be correct if one mole of c2h2 was used in this reaction? one mole of oxygen was used in this reaction. five moles of oxygen were used in this reaction. four moles of carbon dioxide were produced from this reaction. two moles of carbon dioxide were produced from this reaction.

Measurements that have similar values are: a. usually accurate b. sometimes accurate c. always accurate d. never accurate