Oquizy

A car engine produces harmful gases like CO and NO. The catalytic converter uses platinum to convert them into less harmful gases. Which overall change occurs in the redox reaction inside the converter?

CO and NO are both oxidised CO and NO are both reduced CO is oxidised and NO is reduced CO is reduced and NO is oxidised

A student sets up two sealed flasks: one with oxygen and methane, and one with oxygen and nitrogen dioxide. Both are exposed to UV light. Which flask would most likely contribute to the formation of ground-level ozone?

Both flasks equally Neither flask Only the methane flask Only the nitrogen dioxide flask

In a closed system, the reaction between sulfur dioxide, water, and oxygen forms sulfuric acid. Which trend best describes the pH change during this process?

Gradual increase in pH over time Oscillating pH values over time Sharp drop then plateau at low pH Stable pH throughout the reaction

A region experienced unusually high temperatures and smog. Satellite data showed a spike in atmospheric ozone levels. Which combination of gases and conditions most likely caused this?

High CO and low UV levels High NO₂ and strong sunlight High SO₂ and no wind Low NO₂ and high humidity

During Science Club, Xinyi tries to calculate how much CO₂ is formed when 4 moles of carbon monoxide are passed through a catalytic converter.

2 mol 4 mol 6 mol 8 mol

John is solving a greenhouse gas puzzle. If 1 mol of methane (CH₄) releases 890 kJ of energy when burned, how much energy is released by 3 mol of CH₄?

1780 kJ 2670 kJ 3000 kJ 890 kJ

John was puzzled by how CFCs damage the ozone layer. Which correctly explains how CFCs destroy ozone?

CFCs break down ozone directly CFCs prevent UV light from reaching ozone CFCs produce oxygen from water vapour Chlorine radicals from CFCs break down ozone molecules

During a science competition, John and Xinyi were given this data:

- Nitrogen boils at –196°C
- Oxygen boils at –183°C
- Argon boils at –186°C

In fractional distillation of air, in what order will these gases be collected as the liquid air warms?

Argon → Oxygen → Nitrogen Nitrogen → Argon → Oxygen Nitrogen → Oxygen → Argon Oxygen → Argon → Nitrogen

John noticed the greenhouse effect simulation included methane. Which of the following explains why methane contributes more to warming than CO₂, molecule for molecule?

Methane absorbs more infrared radiation Methane reacts with nitrogen Methane traps more UV light Methane turns into CO₂ immediately

Quiz: Chemistry - Maintaining Air Quality