Q1. A salt can be made by reacting an acid with an insoluble base,
A student has a sample of copper (II)oxide.
The student uses this method
Stage 1 pour 50 cm of dilute sulfuric acid into a beaker
Stage 2 warm the acid using a Bunsen bumer
Stage 3 add a small amount of copper (11) oxide to the warm acid and stir the mixture
Stage 4 add further amounts of copper (1) oxide until copper (II)oxide is in excess
Stage 5 filter the mixture
Stage 6 obtain crystals from the fitrate
(a) State why the acid is warmed in stage 2
(b) State how the student would know that the copper (II)oxide is in excess in stage 4
(c) State why the mixture is filtered in stage 5.
() State the color of the filtrate obtained in stage 5.
(Total for question 4 ma

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.