Answer:
Explanation:
When acetic acid solution and barium hydroxide solution react together to give an aqueous solution of barium acetate and water
The balanced chemical reaction will be given by
Answer:
20.2 kJ
Explanation:
Based on the information in the reaction, the amount of heat released per mole of Na₂O₂ (the molar enthalpy) is calculated as follows:
126 kJ / 2 mol = 63 kJ/mol Na₂O₂
The number of moles in 25.0g of Na₂O₂ must be calculated using the molecular weight of Na₂O₂ (77.978 g/mol):
(25.0 g)/(77.978 g/mol) = 0.32060 mol Na₂O₂
Thus, the heat released will be:
(63 kJ/mol)(0.32060 mol) = 20.2 kJ
Trainers use this substance because the reaction of the product on the skin is an exothermic one. This produces a feeling of warmth and heat. Heating an injury like a sprain with warmth or heat increases blood flow to the area and promotes healing as the flow of blood carries the necessary substances for healing.
a. 1.05 x 10⁻³ mol
b. 0.155% w/v
<h3>Further explanation</h3>
Given
50 ml Ca(OH)₂
19.5 ml of 0.1059 N HCl
Required
Amount of Ca(OH)₂
The Ca(OH)₂ concentration in % w/v.
Solution
Titration formula :
M₁V₁n₁=M₂V₂n₂
or
N₁V₁=N₂V₂
n = acid base valence=amount of H⁺/OH⁻(Ca(OH)₂=2, HCl=1)
a.
Input the value(1=Ca(OH)₂, 2= HCl) :
M₂=N₂=0.1059 M
M₁. 50 ml . 2 = 0.1059 . 19.5 . 1
M₁ = 0.021
Amount of Ca(OH)₂ :
mol Ca(OH)₂ = 0.021 x 50 ml = 1.05 mlmol = 1.05 x 10⁻³ mol
b. mass of Ca(OH)₂
= mol x MW
= 1.05 x 10⁻³ mol x 74 g/mol
= 0.0777 g
%w/v = (g solute / volume of solution) x 100
%w/v =( 0.0777 g/ 50 ml) x 100 =0.155% w/v