7. Acids, bases and salts
A section of Chemistry, 0620
Listing 10 of 506 questions
Rhenium is a metal. Describe three physical properties of rhenium. The structure of a rhenium chloride molecule is shown. Cl Cl Cl Cl Re Re Re Cl Cl Cl Cl Cl Determine the simplest formula for this chloride of rhenium. Rhenium oxide is a yellow solid which undergoes sublimation at a low temperature. What is the meaning of the term sublimation? Rhenium oxide reacts with water to form perrhenic acid. Perrhenic acid is strongly acidic. Which one of the following pH values represents an acidic solution? Draw a ring around the correct answer. pH 2 pH 7 pH 9 pH 14 Perrhenic acid reacts with potassium hydroxide. Complete the word equation for this reaction. perrhenic acid + potassium hydroxide → potassium perrhenate + Which one of the following compounds will react with perrhenic acid? Tick one box. ethane hydrochloric acid potassium carbonate sodium chloride Potassium perrhenate has a similar formula to potassium manganate(. Potassium manganate(decomposes to give off oxygen. Describe a test for oxygen. test result
0620_m16_qp_32
THEORY
2016
Paper 3, Variant 2
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Acids have characteristic chemical properties. Describe the reactions of hydrochloric acid with: ● ● calcium oxide ● ● magnesium ● ● a named indicator of your choice. Acids react with alkalis such as sodium hydroxide. What type of chemical reaction is this? Which one of the following pH values is the pH of an aqueous solution of sodiumhydroxide? Draw a circle around the correct answer. pH 2 pH 5 pH 7 pH 13  A mixture of sodiumhydroxide and ammoniumsulfate is warmed gently. State the name of the gas produced. The melting point of sodiumhydroxide is 319 °C. The boiling point of sodiumhydroxide is 1390 °C. Which one of the following statements about sodium hydroxide is correct? Tick one box. Pure sodium hydroxide melts over a range of temperatures. Impure sodium hydroxide has a sharp melting point. Pure sodium hydroxide boils between 319 °C and 1390 °C. Pure sodium hydroxide has a sharp boiling point.  Sodium hydroxide is used in the manufacture of some medicines. Why is it important that the ingredients used in medicines are pure? 
0620_m18_qp_32
THEORY
2018
Paper 3, Variant 2
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Questions Discovered
506