Answer:

Explanation:
Given


Required
Determine the percentage error
First, we need to determine the difference in the measurement




The percentage error is calculated as thus:




<em>approximated</em>
The final volume V₂=4.962 L
<h3>Further explanation</h3>
Given
T₁=20 + 273 = 293 K
P₁= 1 atm
V₁ = 4 L
T₂=100+273 = 373 K
P₂=780 torr=1,02632 atm
Required
The final volume
Solution
Combined gas law :
P₁V₁/T₁=P₂V₂/T₂
Input the value :
V₂=(P₁V₁T₂)/(P₂T₁)
V₂=(1 x 4 x 373)/(1.02632 x 293)
V₂=4.962 L
Answer A )
Potassium chloride
K+ Cl-
hope this helps!.
<u>Answer:</u> The concentration of solution is 0.342 M
<u>Explanation:</u>
To calculate the molarity of solution, we use the equation:

We are given:
Mass of solute (Sodium chloride) = 15 g
Molar mass of sodium chloride = 58.5 g/mol
Volume of solution = 750 mL
Putting values in above equation, we get:

Hence, the concentration of solution is 0.342 M
Explanation:
The solution of the lactic acd and sodium lactate is referred to as a buffer solution.
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. In this case, the weak acid is the lactic acid and the conjugate base is the sodium lactate.
Buffer solutions are generally known to resist change in pH values.
When a strong base (in this case, NaOH) is added to the buffer, the lactic acid will give up its H+ in order to transform the base (OH-) into water (H2O) and the conjugate base, so we have:
HA + OH- → A- + H2O.
Since the added OH- is consumed by this reaction, the pH will change only slightly.
The NaOH reacts with the weak acid present in the buffer sollution.