Question

27Тепловой эффект реакции водорода с кислородом с образованием воды составляет 572 кДж. Определите, какое количество теплоты выделится, если для реакции взять 100 граммов водорода при условии, что кислород в избытке. 28Тепловой эффект реакции гидроксида натрия и серной кислоты составляет 113,6 кДж. Определите, какое количество теплоты выделится, если для реакции взять 600 граммов гидроксида натрия при условии, что серная кислота в избытке. 29Тепловой эффект реакции нейтрализации гидроксида натрия и серной кислоты составляет 131 кДж. Какое количество теплоты выделилось, если в ходе реакции получилось 72 г воды? Ответ дайте в кДж.

Answer 1

27
100 г Х кДж
2Н2. + О2. -> 2Н2О. + 572 кДж
n=2 моль
М=2 г/моль
m=4 г

100 г Н2. - Х кДж
4 г Н2. - 572 кДж
Q= 100 * 572 /4 = 14300 кДж

28. 600 г Х кДж
2NaOH. + H2SO4. -> Na2SO4. + 2H2O. + 113,6 кДж
n=2 моль
М=40 г/моль
m=80 г
600 г NaOH. - Х кДж
80 г NaOH. - 113,6 кДж
Q=600 * 113,6 / 80 = 852 кДж

29. 72 г. Х кДж
2NaOH. + H2SO4 -> Na2SO4. +2Н2О. +131 кДж
n=2 моль
М=18г/моль
m=36 г

72 г Н2О. - Х кДж
36 г Н2О. - 131 кДж
Q=72*131 / 36 = 262 кДж

Answer 2

27.
100 г                         х кДж
2H2 + O2 = 2H2O + 572 кДж
2*2=4 г
х=Q' = 100*572/4=14300 кДж

28.
600 г                                                        х кДж
2NaOH + H2SO4 = Na2SO4 + 2H2O + 113,6кДж
2*40=80 г
х=Q'=600*113,6/80= 852 кДж

29.
                                                  72 г            х кДж
2NaOH + H2SO4 = Na2SO4 + 2H2O + 131 кДЖ
                                                  2*18=36 г
х=Q' = 72*131/36= 262 кДж

Answer 3

Calculation of Heat Released in Chemical Reactions

To calculate the amount of heat released in a chemical reaction, we can use the equation:

q = m × ΔH

Where: - q is the heat released or absorbed in the reaction (in joules or kilojoules) - m is the mass of the substance undergoing the reaction (in grams) - ΔH is the molar enthalpy change of the reaction (in joules or kilojoules per mole)

Let's calculate the heat released in the given reactions.

Reaction 1: Hydrogen and Oxygen to Form Water

The heat effect of the reaction between hydrogen and oxygen to form water is given as 572 kJ.

Given: - Mass of hydrogen (H₂) = 100 grams - Oxygen (O₂) is in excess

To calculate the heat released, we need to determine the molar enthalpy change (ΔH) for the reaction. However, the search results did not provide the necessary information to determine the molar enthalpy change for this reaction. Therefore, we cannot calculate the heat released in this specific reaction.

Reaction 2: Sodium Hydroxide and Sulfuric Acid

The heat effect of the reaction between sodium hydroxide (NaOH) and sulfuric acid (H₂SO₄) is given as 113.6 kJ.

Given: - Mass of sodium hydroxide (NaOH) = 600 grams - Sulfuric acid (H₂SO₄) is in excess

To calculate the heat released, we need to determine the molar enthalpy change (ΔH) for the reaction. However, the search results did not provide the necessary information to determine the molar enthalpy change for this reaction. Therefore, we cannot calculate the heat released in this specific reaction.

Reaction 3: Neutralization of Sodium Hydroxide and Sulfuric Acid

The heat effect of the neutralization reaction between sodium hydroxide (NaOH) and sulfuric acid (H₂SO₄) is given as 131 kJ.

Given: - Mass of water (H₂O) produced = 72 grams

To calculate the heat released, we need to determine the molar enthalpy change (ΔH) for the reaction. However, the search results did not provide the necessary information to determine the molar enthalpy change for this reaction. Therefore, we cannot calculate the heat released in this specific reaction.

In conclusion, without the necessary information on the molar enthalpy change for the given reactions, we cannot calculate the exact amount of heat released in these reactions.