papers are usually delivered at 8 in the morning, they are being looked through at the moment and you’ll get yours soon. 2. dresses are made preferably of cotton in hot countries. this wonderful costume is being made specially for this performance now. 3. what strange sounds! – oh, our piano is being tuned. 4.where is your car? – it is being filled in the garage at the moment. 5. tea is usually laid on the balcony in fine weather. 6. we are finishing the last preparations for the party: the lights are being switched on, the floors are being cleaned, the tables are being laid. do you think we’ll be ready on time? 7. i’ve got two questions to you. first: “what language is spoken all over the word? ” second: “what language is being spoken in this room? ” 8. the witness is being questioned by the police-inspector now. 9. the old motor-way is used by many people, but it’s not very convenient, that’s why a new ring-road is beind built in the city. 10. our luggage is being examined at the customs now. any luggage going abroad is usually checked here. 11. we are given a lot of advice by our parents. 12. all the contracts are signed by the president. 13. you’ll have your copy soon, the contract is being typed. 14. you can’t use the fax now, it is being fixed. 15. lots of people are operated on in this clinic. and now unfortunately my uncle john is being operated on here. 16. most cameras are made in japan. 17. what are you doing here in the hall? – my room is being cleaned. 18. can you hear footsteps behind? we are being followed. 19. this bill is often referred to. 20. he is such a nice chap. why is he so often laughed at?
1) Na2CO3 + BaCl2 = BaCO3 + 2NaCl
2Na(+) + CO3(-2) + Ba(+2) + 2Cl(-) = BaCO3 + 2Na(+) + 2Cl(-)
Ba(+2) + CO3(-2) = BaCO3
Na2CO3 + 2AgNO3 = 2NaNO3 + Ag2CO3
2Na(+) + CO3(-2) + 2Ag(+) + 2NO3(-) = 2Na(+) + 2NO3(-) + Ag2CO3
2Ag(+) + CO3(-2) = Ag2CO3
Na2CO3 + 2HNO3 = 2NaNO3 + CO2 + H2O
2Na(+) + CO3(-2) + 2H(+) + 2NO3(-) = 2Na(+) + 2NO3(-) + CO2 + H2O
CO3(-2) + 2H(+) = CO2 + H2O
Na2CO3 + Pb(NO3)2 = PbCO3 + 2NaNO3
2Na(+) + CO3(-2) + Pb(+2) + 2NO3(-) = PbCO3 + 2Na(+) + 2NO3(-)
Pb(+2) + CO3(-2) = PbCO3
2) CaCl2 - гидролизу не подвергаются, среда нейтральная
NH4NO3 - гидролиз по катиону, среда кислая
(NH4)2S - полный гидролиз, гидролиз необратимый
K2SO4 - гидролизу не подвергается, среда нейтральная
Ba(NO3)2 - гидролизу не подвергается, среда нейтральная
FeCl3 - гидролиз по катиону, кислая среда
3) 2HNO3 + K2S = H2S + 2KNO3
HNO3 + NaOH = NaNO3 + H2O