How many grams of alcohol with a density of 0.900 g/cm3 will have the same volume as 20.0 g of mercury, with a density of 13.6 g/cm3?
a. 15.1
b. 1.32
c. 1.47
d. 22.2
A 15.0 g sample of hydrated copper sulfate was heated to dryness and the new mass measured to be 9.59 g. Calculate the percentage of water in the hydrated crystal. Express your answer to the correct number of significant digits.
a. 36.1%
b. 36%
c. 64%
d. 80%
2006-09-21 15:30:37 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Need helps, Could you please break it down?
2006-09-21 15:36:40 · update #1
First question breaks down as follows
20.0 g of mercury at 13.6 g/cm^3 takes up how much volume?
20g / (13.6 g/cm^3), or about 1.45 cm^3.
How many grams of alcohol in 1.45 cm^3?
1.45 * .9 g or about 1.3, which should be B. from your list.
Your on your own for the second one.
2006-09-21 15:46:06 · answer #1 · answered by Jim T 6 · 0⤊ 0⤋
question 2. 15.0 g-9.59 g=5.41 g (mass of water that is removed); (5.41 g/15.0 g) x100%=36.1%, thus answer is a.
question 1. You need a variable that's constant in bith situations, thus that being the volume in this case. Density= mass(g)/volume(ml). 13.6g/cm3= 20.0g/x; x =1.4706 ml
now you know that the volume for alcohol is also 1.4706 ml, so
0.900 g/cm3= y/1.4706; y= 0.900 g/cm3 x 1.4706= 1.32 grams, thus the answer being b.
2006-09-21 23:09:55 · answer #2 · answered by Natasha B 4 · 0⤊ 0⤋
you know what Natasha is has the solution
For que 1 the answer is indeed B
for que 2 the answer is again B, i.e. 36 % not 36.1% following the rule on significant figures
2006-09-22 04:11:27 · answer #3 · answered by teroy 4 · 0⤊ 0⤋
Do your own dam homework - lazy ***
2006-09-21 22:39:54 · answer #4 · answered by advancedmaster 5 · 0⤊ 0⤋
b and a
2006-09-21 22:45:38 · answer #5 · answered by Anonymous · 0⤊ 0⤋
d and c
2006-09-21 22:32:57 · answer #6 · answered by Lauren 2 · 0⤊ 0⤋