Answer:
B. 0.5 molar
Explanation:
Given data:
Initial concentration = 0.40 M
Initial volume = 750 mL
Final volume =750 - 150 mL = 600 mL
Final concentration = ?
Solution:
Molarity is the number of moles of solutes in litter of solvent. In given problem it is stated that when the solution is uncovered solvent evaporate it means molarity is changed. we can calculate the new molarity with the following formula.
C₁V₁ = C₂V₂
C₁ = initial concentration
V₁ = initial volume
C₂ = final concentration
V₂ = final volume
Now we will put the values in formula.
C₁V₁ = C₂V₂
0.40 M × 750 mL = C₂ × 600 mL
300 M.mL / 600 mL = C₂
0.5 M = C₂
<span>CH3COOH + NaOH = CH3COONa +H2O</span>
<span>Oceanic plates are more dense than continental plates so the oceanic plate dives under the continental plate.
This creates </span><span>subduction</span> zones, in which volcanoes are formed
Answer: pH=2.38
Explanation:
To calculate the pH, let's first write out the equation. Then, we will make an ICE chart. The I in ICE is initial quantity. In this case, it is the initial concentration. The C in ICE is change in each quantity. The E is equilibrium.
HCOOH ⇄ H⁺ + HCOO⁻
I 1.0M 0 0
C -x +x +x
E 1.0-x x x
<u>For the steps below, refer to the ICE chart above.</u>
1. Since we were given the initial of HCOOH, we can fill this into the chart.
2. Since we were not given the initial for H⁺ and HCOO⁻, we will put 0 in their place.
3. For the change, we need to add concentration to the products to make the reaction reach equilibrium. We would add on the products and subtract from the reactants to equalize the reaction. Since we don't know how much the change in, we can use variable x.
4. We were given the Kₐ of the solution. We know
.
5. The problem states that the Kₐ=1.8×10⁻⁴. All we have to so is to plug it in and to solve for x.

6. Once we plug this into the quadratic equation, we get x=0.00415.
7. The equilibrium concentration of [H⁺]=0.00415. pH is -log(H⁺).
-log(0.00415)=2.38
Our pH for the weak acid solution is 2.38.