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Solid sodium hydroxide, NaOH, is dissolved in water and the temperature of the solution increases. Which diagram shows the enthalpy change for dissolving the solid in water? A. Diagram A B. Diagram B C. Diagram C D. Diagram D
Hydrogen atoms in the gas phase combine to form a covalent bond: H(g) + H(g) → H2(g) Which statement describes the energy change? A. Energy is absorbed and ΔH is positive B. Energy is released and ΔH is positive C. Energy is released…
The solid curve in the enthalpy profile below is for a reaction carried out under one set of conditions. The dashed curve is obtained when the same reaction is carried out with one change. Which change is represented by the dashed curve? A. A higher…
Curve X (dashed) shows the volume of oxygen formed when 25 cm3 of 1.0 mol dm−3 hydrogen peroxide solution decomposes in the presence of a manganese(IV) oxide catalyst at 25 °C. 2 H2O2(aq) → O2(g) + 2 H2O(l) Which change would…
The temperature of a sample of an ideal gas falls from 600 K to 150 K. How does the average kinetic energy of the gas particles change? A. It decreases by a factor of 2 B. It decreases by a factor of 4 C. It decreases by a factor of 16 D. It does not change…
The potential energy profile of an exothermic reaction is shown. The vertical arrows I, II and III show three energy changes. Which energy changes would be affected by adding a catalyst? A. I and II only B. I and III only C. II and III only D. I, II and III
A saturated solution of magnesium hydroxide contains undissolved solid. Which change will shift the position of the equilibrium to the right? Mg(OH)2(s) ⇌ Mg2+(aq) + 2 OH−(aq) A. Adding more solid Mg(OH)2 B. Adding dilute hydrochloric acid C.…
Magnesium hydroxide is the active ingredient of some indigestion remedies, which neutralize excess hydrochloric acid in the stomach. (i) Write an equation for the reaction of magnesium hydroxide with hydrochloric acid. (ii) Calculate the mass, in g, of…
Which products are formed when dilute hydrochloric acid reacts with solid calcium carbonate? A. Calcium chloride and water B. Calcium chloride, carbon dioxide and water C. Calcium chloride and hydrogen D. Calcium hydroxide and carbon dioxide
Which reaction is the neutralization of a Brønsted-Lowry acid by a Brønsted-Lowry base? A. Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) B. 2 Mg(s) + O2(g) → 2 MgO(s) C. CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(l) D.…