Answer:
Hydrogen gas
Explanation:
During electrolysis of acidified water, H+ ions are reduced to H2 gas at the negative carbon electrode (cathode) and hence hydrogen gas is liberated at cathode.
The reactions of the human body are exothermic
Answer:
We take 20.0 mL of the 1.0 M fruit drink solution and then add 80.0 mL of water to make 100 mL of a 0.2 M fruit drink solution.
Explanation:
- Using the rule that: the no. of millimoles of a solution before dilution is equal to the no. of millimoles of the solution after the dilution.
<em>(MV) before dilution = (MV) after dilution.</em>
M before dilution = 1.0 M, V before dilution = ??? mL.
M after dilution = 0.2 M, V after dilution = 100 mL.
<em>∴ V before dilution = (MV) after dilution / M before dilution </em>= (0.2 M)(100 mL) / (1.0 M) = <em>20.0 mL.</em>
<em>So, we take 20.0 mL of the 1.0 M fruit drink solution and then add 80.0 mL of water to make 100 mL of a 0.2 M fruit drink solution.</em>
PH is the test of acidity or basicity of a solution. it follows the formula:
pH = pKa + log [salt] / [acid] where NaF is the salt and HF is the acid in this case.
By literature, Ka of HF is 3.5*10^-4
<span>pKa= -log(Ka)=</span><span> 3.46 </span>
<span>pH = pKa + log [NaF / [HF] </span>
4.05 = 3.46 + log [NaF / [HF]
log [NaF / [HF]<span> = 0.59
</span>
[NaF / [HF] = 3.89
