Question

Относительная плотность углеводорода по водороду равна 42. при полном сжигание 0,7 г этого углеводорода получили 1,12 л углекислого газа и 0,9 г воды. Определить молекулярную формулу этого вещества

Answer 1

Решение:  

M(CxHy)=42*2=84г/моль;

n(CnHy)=0,7:84=0,0083моль; n(CO2)=1,12:22,4=0,05моль; n(H2O)=0,9:18=0,05моль;

CxHy + O2 = CO2 + H2O   -объемы приводим к целым числам,делим на0,0083

CxHy + O2 =CO2 + H2O

1CxHy+O2=6CO2+6H2O

x=6;y=6;

ответ:C6H12        

Answer 2

Calculation of Relative Density

To determine the molecular formula of the hydrocarbon, we can start by calculating the relative density of the compound. The relative density of a substance is the ratio of its density to the density of a reference substance, which is usually water.

Given that the relative density of the hydrocarbon with respect to hydrogen is 42, we can use this information to calculate the density of the hydrocarbon.

The relative density (RD) is defined as:

RD = (Density of the substance) / (Density of the reference substance)

In this case, the reference substance is hydrogen. Therefore, we can rewrite the equation as:

RD = (Density of the hydrocarbon) / (Density of hydrogen)

To find the density of the hydrocarbon, we need to know the density of hydrogen. The density of hydrogen is approximately 0.0899 g/L.

Let's calculate the density of the hydrocarbon:

Density of the hydrocarbon = RD * Density of hydrogen

Density of the hydrocarbon = 42 * 0.0899 g/L

Density of the hydrocarbon = 3.767 g/L

Calculation of Moles

Next, we can calculate the number of moles of the hydrocarbon using the given mass of the hydrocarbon.

Given that 0.7 g of the hydrocarbon was completely burned, we can use the molar mass of the hydrocarbon to calculate the number of moles.

To calculate the molar mass, we need to know the molecular formula of the hydrocarbon. Unfortunately, the molecular formula of the hydrocarbon is not provided in the question. Without the molecular formula, we cannot calculate the molar mass or determine the molecular formula of the hydrocarbon.

Therefore, we cannot proceed with the calculation of the molecular formula of the hydrocarbon based on the given information.

If you have any additional information or if there is anything else I can assist you with, please let me know!