Predict the sign of  dalta System for each of the following processes:

a) Molten gold solidifies.

b) Gaseous Cl2 dissociates in the stratosphere to form gaseous Cl atoms.

c) Gaseous CO reacts with gaseous H2 to form liquid methanol, CH3OH.

d) Calcium phosphate precipitates upon mixing Ca(NO3)2 (aq) and (NH4)3PO4 (aq).

Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH₄) and liquid water. Write the equation for this reaction.

Gaseous methane (CH4) reacts with gaseous oxygen gas (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O). If 15.8 g of water is produced from the reaction of 8.18 g of methane and 41.1 g of oxygen gas, calculate the percent yield of water.