Butanoic acid is a natural product and a component of human sweat.
Calculate the value of
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CHEMISTRY, M6 2019 HSC 27
The relationship between the acid dissociation constant,
Assume that the temperature for part (a) and part (b) is 25°C.
- The
of hypochlorous acid is . - Show that the
of the hypochlorite ion, , is . (1 mark)
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- The conjugate base dissociation constant,
, is the equilibrium constant for the following equation: -
- Calculate the pH of a 0.20 mol L¯1 solution of sodium hypochlorite
. (4 mark)
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CHEMISTRY, M6 2020 HSC 33
Excess solid calcium hydroxide is added to a beaker containing 0.100 L of 2.00 mol L¯1 hydrochloric acid and the mixture is allowed to come to equilibrium.
- Show that the amount (in mol) of calcium hydroxide that reacts with the hydrochloric acid is 0.100 mol. (2 marks)
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- It is valid in this instance to make the simplifying assumption that the amount of calcium ions present at equilibrium is equal to the amount generated in the reaction in part (a).
- Calculate the pH of the resulting solution. (4 marks)
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CHEMISTRY, M5 2020 HSC 27
A student makes up a solution of propan-2-amine in water with a concentration of 1.00 mol L ¯1.
- Using structural formulae, complete the equation for the reaction of propan-2-amine with water. (2 marks)
- The equilibrium constant for the reaction of propan-2-amine with water is
. - Calculate the concentration of hydroxide ions in this solution. (3 marks)
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a.
b.
Assume
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a.
♦ Mean mark (a) 48%.
b.
Assume
Mean mark (b) 51%.
CHEMISTRY, M6 2020 HSC 14 MC
The equation for the autoionisation of water is shown.
At 50°C the water ionisation constant,
What is the pH of water at 50°C?
- 5.50
- 6.63
- 6.93
- 7.00