Question

помогите пожалуйста решить!:ЗТермохимическое уравнение реакции горения углерода имеет вид: С+О2=СО2+394 кДж. Раасчитайте массу углерода, вступившего в реакцию, если выделилось 1970 кДж теплоты.

Answer 1

смотри: 1970 кДж - это по условию, а 394 - по уравнению
1970/394 = 5 моль (типа по условию перед всеми в-ми должен стоять коэффициент 5)
тогда n(C) = 5 моль
ну а теперь и массу найдем : m(C0 = n*M = 5*12 = 60 г 

Answer 2

Calculation of the Mass of Carbon in the Combustion Reaction

To calculate the mass of carbon that participated in the combustion reaction, we can use the given thermochemical equation and the amount of heat released.

The thermochemical equation for the combustion of carbon is:

C + O2 → CO2 + 394 kJ

We are given that 1970 kJ of heat was released during the reaction.

To find the mass of carbon, we need to use the stoichiometry of the balanced equation. From the equation, we can see that 1 mole of carbon reacts to form 1 mole of carbon dioxide and releases 394 kJ of heat.

Using the molar mass of carbon (12.01 g/mol) and the molar mass of carbon dioxide (44.01 g/mol), we can set up the following proportion:

12.01 g C / 1 mol C = x g C / 1970 kJ

Solving for x, we can find the mass of carbon:

x = (12.01 g C / 1 mol C) * (1970 kJ / 394 kJ) = 60.55 g

Therefore, the mass of carbon that participated in the combustion reaction is approximately 60.55 grams.

Please note that this calculation assumes that the reaction is complete and that all the carbon reacted to form carbon dioxide.