It stays the same, because the concentration of H+ ions doesn't change.
Answer:
Explanation:
To determine what is been asked in this question, firstly, the formula to determine the number of atoms present in a substance must be used. The formula is
number of atoms = n × 6.02 × 10²³
where n is the number of moles
6.02 × 10²³ is avogadro's number
The number of atoms needed (to be present) has already been provided in the question as 2 × 10²⁴
Thus;
2 × 10²⁴ = n × 6.02 × 10²³
n = 2 × 10²⁴ ÷ 6.02 × 10²³
n = 3.32
The number of moles of carbon that will be placed in the reaction will be 3.32 but to determine the amount/mass of carbon that will be used in the reaction, we will use the formula
n = mass/molar mass
The molar mass of carbon is 12 g/mol
Thus;
3.32 = mass/12
mass = 3.32 × 12
mass = 39.84 g
The mass of carbon that will be required for the reaction will be 39.84, the procedure above shows how to obtain this amount.
Answer:
4
10
Explanation:
The reaction equation is given as;
Ca(OH)₂ → Ca²⁺ + 2OH⁻
Concentration of Ca(OH)₂ = 5 x 10⁻⁵M
Unknown:
pOH of the solution = ?
pH of the solution = ?
Solution:
Solve for the pOH of this solution using the expression below obtained from the ionic product of water;
pOH = ⁻log₁₀[OH⁻]
Ca(OH)₂ → Ca²⁺ + 2OH⁻
1moldm⁻³ 1moldm⁻³ 2 x 1moldm⁻³
5 x 10⁻⁵moldm⁻³ 5 x 10⁻⁵moldm⁻³ 2( 5 x 10⁻⁵moldm⁻³ )
1 x 10⁻⁴moldm⁻³
Therefore;
pOH = -log₁₀ 1 x 10⁻⁴ = 4
Since
pOH + pH = 14
pH = 14 - 4 = 10
