<span>Mg + O2 > MgO. In reactant side, 2 O atoms and 1 Mg are present. In product side, 1 Mg and O atoms are present. Put 2 in product side to balance O atoms and 2 at Mg in reactant side to balance Mg atoms. Therefore the balanced equation becomes, 2Mg + O2 ----> 2MgO. Hope it helps.</span>
Answer:
B?
Explanation:
In the example, the amount of hydrogen is 202,650 x 0.025 / 293.15 x 8.314472 = 2.078 moles. Use the mass of the hydrogen gas to calculate the gas moles directly; divide the hydrogen weight by its molar mass of 2 g/mole. For example, 250 grams (g) of the hydrogen gas corresponds to 250 g / 2 g/mole = 125 moles.
Answer:
30.8 grams of nitric acid are produced
Explanation:
Let's state the reaction:
3 NO₂ + H₂O → 2 HNO₃ + NO
If water is the excess reagent, then the limiting is the gas.
We convert the mass to moles:
45 g . 1 mol/ 46 g = 0.978 moles
Ratio is 3:2. 3 moles of gas can produce 2 moles of acid
Then, 0.978 moles may produce (0.978 . 2) /3 = 0.652 moles of acid
This is the 100% yield, but in this case, the percent yield is 75%
0.652 moles . 0.75 = 0.489 moles
Let's convert the moles to mass → 0.489 mol . 63g / 1mol = 30.8 g
