Figure 1.01a: (a.)The surface of a single grain of table salt.

CRS Question, 6–11

QUESTION

Acetylene torches used for welding work so effectively because of the large release of energy (DH) when acetylene, C2H2, reacts with oxygen. For the combustion of acetylene, DH is approximately –1 300 kJ/mol. What is the value for DH when 1.0 grams of acetylene reacts in this way?

1. Approximately +50 kJ

2. Approximately –50 kJ

3. Approximately +34 000 kJ

4. Approximately –34 000 kJ