16. 4.16 grams of cuprous hydride when dissolved in hydrogen chloride gave 1722 litres of hydrogen at 14o C. and 672 m.m. Find the atomic weight of copper.

17. 7-68 grams of cupric oxide, when heated in hydrogen, left 6.13 grams of the metal. Find the atomic weight

of copper.

CuO + H2 = H2O + Cu.

18. 2 grams of cuprous hydride, when dissolved in hydrogen chloride gave 723 c.c. of hydrogen at 10° C. Find the atomic weight of copper.

19.

Cu ̧H ̧ + 2HCl = Cu ̧Cl ̧ + 2H ̧.

40 grams

2

of copper are boiled with hydrogen sulphate; what volume of sulphur dioxide at 100o C. is given off?

Cu + 2H SO,= CuSO, + 2H,O+SO,.

20. 50 grams of copper are dissolved in hydrogen nitrate, what volume of nitric oxide at 200° C. is evolved?

3Cu + 8HNO2 = 3Cu2NO ̧ + 4H ̧0 + 2NO.

21. What volume of hydrogen sulphide at 30o C. and 800 m.m. is required to precipitate the copper from a solution of 100 grams of crystallized cupric sulphate ?

CuSO 5H2O+ H ̧S = CuS + H2SO ̧ + 5H ̧0.

2

4

22. 0.5965 gram of cupric sulphate was dissolved in water and mixed with hydrogen sulphite and potassium sulphocyanide. The cuprous sulphocyanide weighed 0-2983 gram. What is the percentage of copper in the sulphate ? 2CuSO,5H ̧O + 2KCNS = 2HKSO ̧ + 10H ̧O + Cu ̧C ̧NS.

1. MERCURY-VAPOUR is 6.976 times as heavy as air,

its double-density referred to hydrogen.

find

2. 100 volumes of mercury at 0° C. (▲ 13·596) become 102 volumes at 110° C. Find the density of the metal at the higher temperature.

3. What volume of sulphur dioxide is formed on roasting 8000 grams of cinnabar?

HgS+O2 = Hg + SO,.

4. 59.19 grams of mercuric oxide when heated in hydrogen left 54.8 grams of mercury. Find the atomic weight of the metal.

to

5. 1000 c.c. of mercury at 0° C. (▲ 13·596) are cooled

- 40° C.; what is the volume of the solid mercury (A 14.39) ?

6. Find the percentage composition of turpeth-mineral (HgSO. 2HgO).

7. Find the percentage composition of mercuric hydronitrate (HgHNO1).

8. Find the percentage composition of mercuric iodide (HgI,).

Find

9. 20 grams of sodium amalgam, when placed in water, gave 6.236 litres of hydrogen at 3o C. and 480 m.m. the percentage of sodium in the amalgam.

Na + H2O = HNaO + H.

10. A kilogram of mercury at 100° C. was mixed with a kilogram of water at 10° C., and the temperature of the. mixture was found to be 13° C. What is the specific heat of mercury?

11. An iron bottle contains 70 lbs. of mercury (A 13·56), what is its capacity in litres?

12. Find the formula of cadmium amalgam containing mercury 78.26 per cent., and cadmium 21.74 per cent.

13. 100 c.c. of mercury (A 13.56) are warmed with hydrogen nitrate, what volume of nitric oxide at 26° C. is evolved?

3Hg+8HNO,=3Hg2NO, + 4H ̧0 + 2NO.

2

14. What volume of mercury (▲ 13.5) and mass of mercuric chloride are required to form 3 kilos. of mercurous chloride?

1

Hg + HgCl2 = Hg,Cl ̧.

15. The coefficient of expansion of mercury for 1° C. is 550 of its volume at 0° C. The density of mercury at 0° C. is 13.596, what is the density of the metal at 15o C ?

16.

What volume of cyanogen at 150° C. is given off on heating 100 grams of mercuric cyanide ?

HgC.N2 = Hg + C ̧N ̧.

17. 70 grams of mercuric oxide are heated, what volume of oxygen at 20° C. and 740 m.m. is given off?

HgO= Hg + 0.

18.

Excess of mercury is heated in 10 litres of air at

14o C., how much mercuric oxide is formed?

Hg + 0 = HgO.

19. What volume of hydrogen sulphide at 10° C. and 780 m.m. is required to precipitate the mercury from a solution of 126 grams of mercuric cyanide ?

HgC,N2+H,S= HgS+ 2HCN.

20. How many grams do 500 c.c. of the vapour of mercuric chloride (HgCl2) at 350° C. weigh?

21. A glass bulb weighing 430 grains, when filled with mercury at 0° C. weighs 1510 grains. It is placed in hot oil, and after cooling to 0°C. weighs 1490 grains. If the coefficient of apparent expansion of mercury in glass be so, at what temperature Centigrade was the oil?

22. 15 grams of mercury are found to unite with 1.2 grams of oxygen to form mercuric oxide, the molecule of which is believed to consist of one atom of mercury united with one atom of oxygen. One litre of mercury vapour reduced by calculation to 0°C. and 760 m.m. is found to weigh 8.923 grams. What can be deduced from these data about the atomic and molecular weights of mercury?

23. The vapour of mercurous chloride is 8.21 times as heavy as air, what is its apparent molecular weight?

One volume of tin (A 7.3) combines without change of volume with two volumes of mercury (A 13.56). Find the percentage composition and density of the alloy.

25. What column of mercury at 15° C. produces a pressure equal to that of a column of water of 273 m.m. at 20° C. ?

1. A GRAM of silver (▲ 10·5) can be drawn into a wire 2600 metres in length. Find the diameter of the wire.

2. Find the symbol of Proustite which contains silver 65.45 per cent., sulphur 19.39 per cent., and arsenic 15.16 per cent.

3. Mint silver is an alloy of 7.5 per cent. of copper (A 8.9) with 92.5 per cent. of silver (▲ 10·5), and its density is found to be 10.2. What would be the density of the alloy if no change of volume took place, and what do 100 volumes of the two metals occupy after the fusion?

4. How many pounds does a sheet of silver (A 10·5) a yard long, a foot wide, and an inch thick weigh?

5. A grain of silver (A 10.5) can be drawn into a wire 400 feet long, what is the radius of the wire in millimetres? 6. A shilling weighs 87.27 grains of which 80-727 are silver. How many shillings can be made from a ton of

silver and how many grains do they weigh?

7. 10 grams of silver are heated in sulphur vapour, how much silver sulphide is formed?