Chemistry grd 11
posted by Tarkan .
Provided with enough heat, magnesium and oxygen can undergo a synthesis reaction. How much magnesium oxide is produced if 50g of Mg is reacted with 50g of oxygen?
This is a limiting reagent problem. How do you know that? Because BOTH reactants are given instead of just one. Basically, one works two simple stoichiometry problems.
1, Write the equation.
2Mg + O2 ==> 2MgO
2. Convert 50 g Mg to moles. moles = grams/molar mass.
3. Convert 50 g oxygen to moles. Same procedure.
4. Using the coefficients in the balanced equation, convert moles Mg to moles MgO.
5. Same procedure, convert moles oxygen to moles MgO.
6. It is likely that the moles MgO formed from the two previous steps will not agree which means one of them is wrong. The correct answer in limiting reagent problems is ALWAYS the smaller value and the reagent producing that number is the limiting regent.
7. If you want the answer in grams, convert mols to grams. g = mols MgO x molar mass MgO.
Hey thank u for ur answer ... but can u show me with steps from question 4 to 6 please because I didn't get it what u mean there and please can u tell me what the answer will be thank you .....