Question

При нагревании 12,8 г белого кристаллического вещ-ва, оно полностью разложилось на азот и воду.Объём азота 4.48 л. Определите какое вещ-во было нагрето.

Answer 1

 

NxHyOz=N2+H2O
n(N2)=4,48/22,4=0,2; n(N)=0,4; m(N2)=0,2*28=5,6
m(H2O)=12,8-5,6=7,2; m(O)=7,2:9*8=6,4; n(O)=6,4/16=0,4
                                  m(H)=7,2:9*1=0,8; n(H)=0,8/1=0,8
                                    0,4: 0,8:0,4
                                      2: 4 :2
ответ:NH4NO2.

Answer 2

Identification of the Substance

To determine the substance that was heated and completely decomposed into nitrogen and water, we need to analyze the given information.

According to the information provided, 12.8 grams of a white crystalline substance were heated, resulting in the complete decomposition of the substance into nitrogen and water. Additionally, the volume of nitrogen produced was given as 4.48 liters.

To identify the substance, we can use the molar volume of gases at standard temperature and pressure (STP). At STP, 1 mole of any gas occupies a volume of 22.4 liters. By comparing the volume of nitrogen produced (4.48 liters) to the molar volume at STP (22.4 liters), we can determine the number of moles of nitrogen produced.

Using the ideal gas law, we can calculate the number of moles of nitrogen:

n = V / Vm

Where: - n is the number of moles of nitrogen - V is the volume of nitrogen produced (4.48 liters) - Vm is the molar volume of gas at STP (22.4 liters)

Substituting the values into the equation:

n = 4.48 L / 22.4 L/mol = 0.2 mol

Since the decomposition of the substance resulted in the formation of nitrogen and water, we can conclude that the substance heated was ammonium nitrate (NH4NO3). When ammonium nitrate decomposes, it produces nitrogen gas (N2) and water (H2O) as the products.

Please note that the identification of the substance is based on the given information and the assumption that the decomposition reaction is complete.

Conclusion

Based on the given information, the substance that was heated and completely decomposed into nitrogen and water is likely ammonium nitrate (NH4NO3).