| 1. | 19.98 K J | 2. | 200 J |
| 3. | 1999 J | 4. | 1.9988 kJ |
Find the amount of heat released when 35.0 g of CO₂ is formed from the combustion of carbon in dioxygen gas. Given that the enthalpy of combustion of carbon to carbon dioxide is −390.0 kJ mol⁻¹.
| 1. | \(310~\text{kJ}\) | 2. | \(490~\text{kJ}\) |
| 3. | \(245~\text{kJ}\) | 4. | \(700~\text{kJ}\) |
| 1. | \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) | 2. | \(\Delta_{\mathrm{r}} \mathrm{H}<0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0 \) |
| 3. | \(\Delta_{\mathrm{r}} \mathrm{H}<0 \) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) | 4. | \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0\) |
The standard enthalpy of vaporization for water at 100 oC is 40.66 kJ mol–1. The internal energy of vaporization of water at 100 oC (in kJ mol–1) is:
(Assume water vapour behaves like an ideal gas.)
| 1. | +37.56 | 2. | –43.76 |
| 3. | +43.76 | 4. | +40.66 |