M2CO3 ( M is a metal)
5,22 g dissolved in H2O and reacted with HCl
CO3(-2) (aq) + 2H+ (aq) --> CO2 (g) + H2O (l)
CO2 produced and collecting over H2O . 2.0L at 25 C P= 475 mmHg
Vapour pressure of H2O at 25 C = 23,8 mmHg
Then Which metal is M ?
Ptotal = PH2O + PCO2; solve for PCO2
I've ignored the solubility of CO2 in H2O.
PCO2 = (475-23.8)/760
Use PV = nRT and solve for n, then
n = grams/molar mass. solve for molar mass M2CO3. Then subtract C and 3*O and find 2M and divide by 2 for M. Identify the element from the periodic table.
by using your way, i found its molar mass 48.74. but there is no elemens have this molar mass. titanium has 47,867 ; vanadium has 50.94. What should i do now ?
ok i forgot dividing by 2 (: thanks a lot ;)
To determine the identity of the metal, we need to calculate the moles of CO2 produced and use the stoichiometric ratio between CO2 and M2CO3. Here are the steps to follow:
1. Convert the mass of M2CO3 to moles:
- The molar mass of M2CO3 can be calculated by summing the atomic masses of the metal M and the carbonate group (CO3).
- Look up the atomic mass of the metal M in the periodic table and multiply it by 2 to account for the subscripts.
- Add the molar mass of the CO3 group, which is the sum of the atomic masses of one carbon atom (C) and three oxygen atoms (O).
- Divide the given mass (5.22 g) by the molar mass to obtain the moles of M2CO3.
2. Use the stoichiometric ratio to calculate the moles of CO2:
- According to the balanced equation, each mole of M2CO3 produces one mole of CO2.
- Therefore, the number of moles of CO2 will be equal to the moles of M2CO3.
3. Convert the volume of CO2 to moles:
- Apply the ideal gas law equation, PV = nRT, to calculate the moles of CO2.
- Rearrange the equation to solve for moles (n): n = PV / RT.
- Plug in the given values, such as the pressure (475 mmHg), volume (2.0 L), temperature (25°C converted to Kelvin), and the ideal gas constant (R).
4. Compare the moles of CO2 and M2CO3 to determine the ratio:
- Divide the moles of CO2 by the moles of M2CO3.
- Remember that the stoichiometric ratio between CO2 and M2CO3 is 1:1.
- If the ratio is 1, it means that the moles of CO2 are equal to the moles of M2CO3, indicating that M has a valency of 2. The metal in this case will be divalent.
Once you have performed these calculations, you will be able to determine the identity of the metal (M) in M2CO3.