Answer:
Total percent of magnesium in sample = 25.5%
Explanation:
Given:
Mass of magnesium = 24 gram
Mass of chlorine = 70 gram
Find:
Total percent of magnesium in sample = ?
Computation:
Total mass of sample = Mass of magnesium + Mass of chlorine
Total mass of sample = 24 gram + 70 gram
Total mass of sample = 94 gram
Total percent of magnesium in sample = [Mass of magnesium / Total mass of sample]100
Total percent of magnesium in sample = [24/94]100
Total percent of magnesium in sample = [0.255]100
Total percent of magnesium in sample = 25.5%
Answer:
2Al+1.5O2→Al2O3
Thus, 2 mol of Al combine with 1.5 mol of oxygen to form 1 mol of Al2O3.
2 mol of Al corresponds to 2×27=54 g.
Thus, the weight of Al used in the reaction is 54 g.
Answer:
158g
Explanation:
To calculate the "weight" (mass) of ethyl alcohol, we have to use this formula:
- Density will have units of gmL when dealing with a liquid or units of gcm3 when dealing with a solid.
The mass has units of grams, g.
The volume will have units of mL or cm3
We are given the density and volume, both of which have good units so all we have to do is rearrange the equation to solve for the mass:
density×volume=massvolume×volume
Density×Volume = Mass
0.789gmL×200.0mL
Thus, ethyl alcohol weighs 158g.
Number 4 is Global Warming
