Answer:
Explanation:
1. To identify what's been oxidised and what's been reduced in a redox reaction
2. In naming compounds
3. To work out reacting proportions in titration reactions
Answer: B) KCl
Explanation:
It is an odourless gas with a melting point of of 770°c and a boiling point of about 1420°c, it exists in a white crystalline solid form. KCl is highly water soluble and also soluble in other variety of polar solvent but insoluble in many organic solvents.
[H⁺]=6.696 x 10⁻⁵
pH = 4.174
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Further explanation
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Given
The concentration of 0.000295 M (2.95 x 10⁻⁴ M) butanoic acid solution
Required
the [H+] and pH
Solution
Butanoic acid is the carboxylic acid group. Carboxylic acids are weak acids
For weak acid :
![\tt [H^+]=\sqrt{Ka.M}](https://tex.z-dn.net/?f=%5Ctt%20%5BH%5E%2B%5D%3D%5Csqrt%7BKa.M%7D)
Input the value :
[H⁺]=√1.52 x 10⁻⁵ x 2.95 x 10⁻⁴
[H⁺]=6.696 x 10⁻⁵
pH = - log [H⁺]
pH = - log 6.696 x 10⁻⁵
pH = 5 - log 6.696
pH = 4.174
Answer is: the molar mass of gas is 82.83 g/mol.
m(gas) = 55.50 g; mass of gas.
V(gas) = 15.0 L; volume of gas.
Vm = 22.4 L/mol; molar volume of gas on STP.
n(gas) = V(gas) ÷ Vm.
n(gas) = 15 L ÷ 22.4 L/mol.
n(gas) = 0.67 mol; amount of gas.
M(gas) = m(gas) ÷ n(gas).
M(gas) = 55.5 g ÷ 0.67 mol.
M(gas) = 82.83 g/mol.