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Ozone, O3, absorbs ultraviolet radiation with a wavelength of 300 nm and dissociates. Oxygen, O2, does not dissociate at this wavelength. Which comparison of the bonds in O3 with the bond in O2 is correct? A. Longer and weaker B.…
4-Nitrophenol can act as an acid-base indicator. Its acid form, HIn, is colourless and its conjugate base, In−, is yellow. Explain how 4-nitrophenol acts as an acid-base indicator as the pH increases.
What is the enthalpy change for the following reaction? CO2(g) + 4 H2(g) → CH4(g) + 2 H2O(l) A. +75 + 572 − 394 B. −75 − 572 − 394 C. +75 − 572 + 394 D. −75 − 572 + 394
Outline what happens to a molecule of methane, a greenhouse gas, when it absorbs infrared radiation.
The global warming potential (GWP) of a gas compares the heat it absorbs with the heat absorbed by an equal mass of carbon dioxide. The GWP of the refrigerant C2H2F4 is approximately 1300. Estimate the heat absorbed by one mole of C2H2F4 relative…
The standard enthalpy change of formation of hydrogen chloride gas is −92 kJ mol−1. How much energy, in kJ, is released in the following reaction? H2(g) + Cl2(g) → 2 HCl(g) A. 46 B. 92 C. 368 D. 184
Which allotrope of oxygen, O2 or O3, has the longer bond between oxygen atoms, and which is dissociated by ultraviolet radiation of the longer wavelength? A. Longer bond: ozone; longer wavelength: ozone B. Longer bond: oxygen; longer wavelength:…
When 50 cm3 of 1.0 mol dm−3 HNO3 is mixed with 50 cm3 of 1.0 mol dm−3 KOH in a calorimeter, the temperature of the solution rises by 6.0 °C. What is the temperature rise, in °C, when 50…
(i) Write the balanced equation for photosynthesis, in which glucose is formed. (ii) Explain how the large-scale planting of fast-growing trees is intended to reduce the rate of global warming.
Both hydrogen and methanol can be used as fuels in fuel cells. Outline one way in which a fuel cell differs from a primary (voltaic) cell.