Answer: The molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.
Explanation:
Given:
= 43.6 mL,
= 0.125 M
= 25.0 mL,
= ?
Formula used to calculate the concentration of acid is as follows.

Substitute the values into above formula.

Thus, we can conclude that the molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.
Answer:
Explanation:
A physical change is a change in which the physical properties of matter are altered. These are properties are the forms and state.
Most physical changes are easily reversible and are pure state changes.
They do not lead to the production of new compounds.
They involve no mass change and requires little to no energy.
Examples are melting, boiling, freezing, sublimation e.t.c
Answer:
Mass of water = 41.8 g
Explanation:
Given data:
Mass of water = ?
Change in temperature = 3.0 °C
Specific heat capacity = 4.184 j/g.°C
Heat absorbed = 525 j
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 3.0°C
Now we will put the values in formula.
525 J = m × 4.184 j/g.°C × 3.0°C
525 J = m × 12.552 j/g
m = 525 J/ 12.552 j/g
m = 41.8 g
please have look at Periodic table , you will solve it yourself !