Question

1. Расставьте коэффициенты, определите тип реакции:а) Mg + N2 →Mg3N2б) C +Cr2 O3→ CO2 +Cr в) HNO3 + CaO→ Ca(NO3)2+H2O г ) Na + H2O → NaOH+ H2↑ д) Ba O+ H2SO4 → BaSO4 ↓+ H2O2. Дописать уравнения реакций, расставить коэффициенты, назвать сложные вещества.а) Реакция соединения: Al+ O2 → б) ) Реакция соединения: Mg +Cl2→ в) Реакция замещения: MnO2 + H2 → г ) Реакция обмена: Al2 O3 + H2SO4 → 3 . По уравнению реакции CuCl2 +Mg →MgCl2 +Cu, вычислите количество вещества меди , если в реакцию с хлоридом меди (II) вступило 480 г магния. 4. Какие реакции называются экзотермическими и эндотермическими реакциями? ребят, помогите пожалуйста... понимала химию только в начале года, а потом она начала объяснять всё сумбурно и я никак не понимаю эту контрольную работу... в первом триместре вообще пять... а сейчас 2 по контрольной.

Answer 1

а) 3Mg + N2 →Mg3N2 (соединения)
б) 3C +2Cr2O3→ 3CO2 +4Cr (замещения)
в) 2HNO3 + CaO→ Ca(NO3)2+H2O (обмена)
г) 2Na + 2H2O → 2NaOH+ H2↑ (замещения)
д) BaO+ H2SO4 → BaSO4↓+ H2O (обмена)

а) Реакция соединения: 4Al+ 3O2 → 2Al2O3(оксид алюминия)
б) Реакция соединения:  Mg +Cl2→MgCl2 (хлорид магния)
в) Реакция замещения:  MnO2 + 2H2 → 2H2O+Mn (вода)
г ) Реакция обмена: Al2O3 + 3H2SO4 → Al2(SO4)3 + 3Н2О (Сульфат алюминия и вода)

3 . По уравнению реакции , вычислите количество вещества меди , если  в реакцию с хлоридом меди (II) вступило 480 г магния.
составляем пропорцию:

             480г                х г
CuCl2 +Mg →MgCl2 +Cu
             24г/моль         64г/моль

х = 1280 граммов меди

4. При экзотермических реакциях теплота выделяется (например, горение)
При эндотермических - теплота поглощается

Answer 2

Reaction Equations and Types of Reactions

a) The reaction equation is: Mg + N2 → Mg3N2. This is a combination/synthesis reaction where two or more substances combine to form a single compound. [[1]]

b) The reaction equation is: C + Cr2O3 → CO2 + Cr. This is a redox reaction where carbon (C) is oxidized and chromium (Cr) is reduced. [[2]]

c) The reaction equation is: HNO3 + CaO → Ca(NO3)2 + H2O. This is a double displacement reaction where the positive ions of two compounds exchange places. [[3]]

d) The reaction equation is: Na + H2O → NaOH + H2↑. This is a displacement reaction where sodium (Na) displaces hydrogen (H) from water. [[4]]

e) The reaction equation is: BaO + H2SO4 → BaSO4↓ + H2O. This is a double displacement reaction where the positive ions of two compounds exchange places. The formation of a precipitate (BaSO4) indicates the reaction. [[5]]

Additional Reaction Equations

a) The reaction equation is: 2Al + 3O2 → 2Al2O3. This is a combination/synthesis reaction where two or more substances combine to form a single compound. [[6]]

b) The reaction equation is: Mg + Cl2 → MgCl2. This is a combination/synthesis reaction where two or more substances combine to form a single compound. [[7]]

c) The reaction equation is: MnO2 + 4H2 → Mn + 4H2O. This is a redox reaction where manganese dioxide (MnO2) is reduced and hydrogen (H2) is oxidized. [[8]]

d) The reaction equation is: 2Al2O3 + 3H2SO4 → Al2(SO4)3 + 3H2O. This is a double displacement reaction where the positive ions of two compounds exchange places. [[9]]

Calculation of Amount of Copper (Cu) in the Reaction

The reaction equation is: CuCl2 + Mg → MgCl2 + Cu. Given that 480 g of magnesium (Mg) is used in the reaction, we can calculate the amount of copper (Cu) produced.

The molar mass of magnesium (Mg) is 24.31 g/mol, and the molar mass of copper (Cu) is 63.55 g/mol.

To calculate the number of moles of magnesium (Mg): Number of moles = Mass / Molar mass Number of moles of Mg = 480 g / 24.31 g/mol = 19.75 mol

According to the balanced equation, the stoichiometric ratio between magnesium (Mg) and copper (Cu) is 1:1. Therefore, the number of moles of copper (Cu) produced is also 19.75 mol.

To calculate the mass of copper (Cu): Mass = Number of moles × Molar mass Mass of Cu = 19.75 mol × 63.55 g/mol = 1254.21 g

Therefore, the amount of copper (Cu) produced in the reaction is 1254.21 g.

Exothermic and Endothermic Reactions

Exothermic reactions release energy in the form of heat to the surroundings. The temperature of the surroundings increases during an exothermic reaction. Examples of exothermic reactions include combustion reactions and neutralization reactions.

Endothermic reactions absorb energy from the surroundings. The temperature of the surroundings decreases during an endothermic reaction. Examples of endothermic reactions include the process of photosynthesis and the reaction between baking soda and vinegar.

I hope this helps! Let me know if you have any further questions.