It's D, all of the claims are true about oxidation reactions :)
I believe the correct answers from the choices listed above are the second and the last option. At constant pressure, the systems 2A(g) + B(g) ---> 4C(g) and 2C(g) A(s) + B(s) ---> C(g) produces work to the surroundings. <span>When a gas is evolved during a chemical reaction, the gas can be imagined as displacing the atmosphere - pushing it back against the atmospheric pressure. The work done is therefore V*P where V is the volume of gas evolved, and P is the atmospheric pressure. </span>
<h3>Answer:</h3>
2.6 × 10⁻³ g (Or) 0.0026 g
<h3>Data Given;</h3>
Mass of Oxygen = 1.38 × 10⁻³ g
Mass of Silicon = 0.00122 g = 1.22 × 10⁻³ g
<h3>Solution:</h3>
The total weight of grain of sand is calculated by adding the masses of Oxygen and Silicon as,
Total Weight = Mass of Oxygen + Mass of Silicon
Putting values,
Total Weight = 1.38 × 10⁻³ g + 1.22 × 10⁻³ g
Total weight = 2.6 × 10⁻³ g
Or,
Total weight = 0.0026 g