Answer:
Explanation:
Molecular equation for the reaction:
HI(aq) + KOH(aq) --> KI(aq) + H2O(l)
Ionic equation
K+(aq) + OH-(aq) + H+(aq) + I-(aq) --> K+(aq) + I-(aq) + H2O(l)
Net ionic equation:
H+(aq) + OH-(aq) --> H2O(l)
Answer:
Mass = 20,000 g
Explanation:
Given data:
Mass of MgO formed = ?
Mass of Mg react = 12 Kg (12 Kg × 1000/1 Kg = 12000 g)
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 12000 g/ 24 g/mol
Number of moles = 500 mol
Now we will compare the moles of Mg and MgO.
Mg : MgO
2 : 2
500 : 500
Mass of MgO:
Mass = number of moles × molar mass
Mass = 500 mol × 40 g/mol
Mass = 20,000 g
The balanced chemical reaction is:
CH4 + 2O2 —> CO2 + 2H2O
You need to convert mass to moles (divide by molar mass):
CH4 moles = 5 / 16 = 0.31 mol
O2 moles = 5 / 32 = 0.16 mol
To figure out which reactant is limiting, divide the actual moles by the corresponding coefficient in the reaction:
CH4: 0.31 / 1 = 0.31
O2: 0.16 / 2 = 0.08
O2 is the lower number, so it is the limiting reactant. From the reaction we know it takes 2 moles of O2 to react with each mole of CH4. Therefore, for however many moles of O2 we actually have, half as many moles of CH4 will react. Since we have 0.16 mol of O2, only 0.08 mol of CH4 will react, leaving behind 0.31 - 0.08 = 0.23 mol of CH4.
Now convert back to mass (multiply by molar mass) to find the mass of CH4 remaining:
0.23 x 16 = 3.68g
The closest answer is B.
