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?
ответ:
дано:
m(картофеля)=1620 кг
w((с6н10o5)n)=20%
¥(c6h12o6)=75%
найти: m(c6h12o6)=?
решение :
находим массу крахмала в картофеле :
m((c6h10o5)n)=w*m(картофеля)/100= 20*1620/100=324 кг
находим молярную массу крахмала :
m((c6h10o5)n)=(12*6+1*10+16*5)*n=(82+80)n=162n кг/кмоль
находим количество вещества крахмала:
n((c6h10o5)n)=m/m=324/162n= 2/n кмоль
составляем уравнение реакции :
(c6h10o5)n+nh2o=> nc6h12o6
составляем пропорцию , в которой за х берем количество вещества глюкозы:
x кмоль /n кмоль = 2/n кмоль/1 кмоль
отсюда:
x/n=2/n
получаем:
x=2n/n=2 кмоль
находим молярную массу глюкозы:
m(c6h12o6)=12*6+1*12+16*6=72+12+96=72+108=180 кг/кмоль
находим теоретическую массу глюкозы :
m(теор)(c6h12o6)=n*m=2*180=360 кг
находим практическую массу глюкозы :
m(практ)(c6h12o6)=¥*m(теор)/100=75*360/100=270 кг
ответ: 270 кг
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объяснение:
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?