Летние международные олимпиады для 1-11 классов

# Уроки "The thermal effect of a chemical reaction." 1. What is the mass of iron converted to iron (III) oxide, if the reaction yielded 112 kJ of heat? Thermochemical reaction equation: 3Fe + 2О2 = Fe3О4 +1118 kJ. given: Q1 = 112 kJ find: m(Fe) - ? Solution: 1118 kJ ------ 3 mol Fe, 112 kJ ------- х mol Fe. х= (112 kJ • 3 mol)/(1118 kJ)=3 mol М(Fе) = 56 g/mol m(Fe) = 0,3 mol • 56 g/mol = 16,8 g. Answer:m(Fe) = 16,8 g.
Просмотр
содержимого документа

The thermal effect of a chemical reaction.

1. What is the mass of iron converted to iron (III) oxide, if the reaction yielded 112 kJ of heat? Thermochemical reaction equation: 3Fe + 2О2 = Fe3О4 +1118 kJ.

given:

find:

### Answer:m(Fe) = 16,8 g.

2. The reaction equations the decomposition of mercury (II) oxide:

2HgO = 2Hg + O2 -180 kJ. Determine the amount of heat needed to decompose 100 g of mercury (II) oxide.

given:

find:

### Answer:Q = 41,5 kJ

3. The reaction equations the decomposition of mercury (II) oxide:

2HgO = 2Hg + O2 -180 kJ. Determine the mass  formed mercury  if a at during the reaction was absorbed 36 kJ of heat.

given:

find:

### Answer:m(Нg) = 80,4 g.

4. The reaction equations  the decomposition of mercury (II) oxide:

2HgO = 2Hg + O2 -180 kJ. Determine the amount of heat absorbed during the formation of 0.5 mol of mercury.

given:

find:

### Answer:Q = 45 kJ

5. The reaction equations the decomposition of mercury (II) oxide:

2HgO = 2Hg + O2 -180 kJ. Determine the amount of oxygen released, if this absorbs 100 kJ of heat.

given:

find:

### Answer:ν(О2) = 0,556 mol.

Информация о публикации
Загружено: 10 мая
Просмотров: 804
Скачиваний: 1
Химия, 8 класс, Тесты

### Проверьте знания своих учеников интересными заданиями

Красочные наградные дипломы и сертификаты для участников, свидетельства и благодарности каждому учителю, ежемесячный розыгрыш ценных призов!