SECTION A For these questions, your equation will be straight forward to balance.

In a titration, 20 cm3 of 2.0 mol dm-3 HCl reacted with 25 cm3 of NaOH. What was the concentration of the sodium hydroxide?

In a titration, 20 cm3 of 0.2 mol dm-3 HCl reacted with 50 cm3 of NaOH. What was the concentration of the sodium hydroxide?

In a titration, 20 cm3 of 0.15 mol dm-3 HCl reacted with 25 cm3 of NaOH. What was the concentration of the sodium hydroxide?

In a titration, 20 cm3 of 1.14 mol dm-3 HCl reacted with 25 cm3 of NaOH. What was the concentration of the sodium hydroxide?

20cm=the length of the causation that it loads about the contrasting of the solution it is an easy question to answer it just has too many parts I answered one and I hope it helped to give you a hint towards solving the whole thing good luck

Explanation:

I tried!

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.