Thursday
April 24, 2014

Homework Help: Chemistry

Posted by Mattt K on Sunday, October 25, 2009 at 5:17am.

Are these correct?

1. What is the formula mass for Mg(ClO3)2?
mg=24.31
cl=35.45 x 2 = 70.9
o=16 x 6 = 96
24.31+70.9+96= Answer:191.2 amu

2.How many molecules of CO2 are in 4.5 moles of CO2?
4.5 x 6.022 x10^23=Answer 2.7x10^24

3.How many grams are in 9.21 moles of H2CO3?
h=1.008 x2=2.016
c=12.01
o=16 x3=48
2.016+12.01+48=62.026g/mol
62.026 x 9.21=Answer 571g

4.How many moles are present in 88.2 grams of NaCl?
na=22.99
cl=35.45
22.99+35.45=58.44g/mol
88.2/58.44= Answer 1.51 mol

5. The percent composition of water is
A. 7% H, 33% O
B. 2 H, 1 O
C. 11% H, 89% O
D. 2 H, 16 O
E. 5.9%H, 94.1%O

water=h2o
h=1.008 x 2=2.016
0=16
2.016+16=18.016
2.016/18.016= 11%
16/18.016=89%
Answer= C. 11% H, 89% O

Thank you for the help. This has been a challenging chapter for me and I want to make sure I am doing it correctly.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

CHEM - Magnesium has an average atomic mass of 24.3068 amu and has three ...
statistics - An experimental egg farm is raising chickens to produce low ...
Math - Pls check (38+4^2)-9 24+16 40-9 31 6(10+6)-6^2 616 96-6^2 96-36 60
Chemistry - Magnesium has three naturally occurring isotopes: 24 Mg (23.985 amu...
Chemistry - If 1.88 g of copper(II) chloride dihydrate is reduced by Mg(s), ...
Chemistry - Can someone tell me if I have this correct, I am leaving something ...
Chemistry - Mg(s) + 2 HCl(aq) --> MgCl2(aq) + H2 (g) DeltaH= -4.6x10^2 kJ How...
CHEMISTRY - Given that Mg(ClO3)2 decomposes into magnesium chloride and oxygen: ...
CHEMISTRY - Given that Mg(ClO3)2 decomposes into magnesium chloride and oxygen: ...
Ap Chemistry - Posted by Jake on Sunday, September 23, 2007 at 1:08pm. My ...

Search
Members