Answer:
A decrease in [H3O+] and an increase in pH (option a)
Explanation:
Equilibrium of water is shown in this equation
2H₂O ⇄ H₃O⁺ + OH⁻
When you add NaOH, you are modifying [OH⁻]
NaOH → Na⁺ + OH⁻
In equilibrium of water, the [OH⁻] increases
2H₂O ⇄ ↓ H₃O⁺ + OH⁻ ↑
As the [OH⁻] increases, by Le Chatellier, the equilibrium tends to decrease [H₃O⁺].
If the [OH⁻] is higher, pH is also high so the solution of water and sodium hydroxide would be totally basic.
By breaking the hydrogen bonds that cause surface tension
<u>Answer:</u> The volume of stock solution needed is 90 mL
<u>Explanation:</u>
To calculate the molarity of the diluted solution, we use the equation:

where,
are the molarity and volume of the stock sulfuric acid solution
are the molarity and volume of diluted sulfuric acid solution
We are given:

Putting values in above equation, we get:

Hence, the volume of stock solution needed is 90 mL
C. Sn (tin) is a metal, Si (silicon) is a metalloid, and C (carbon) is a nonmetal