# annabel

Most popular questions and responses by annabel
1. ## Chemistry

a mixture of 4.00 moles of hydrogen and 3.00 moles of oxygen is ignited, forming water. what is the maximum amount of water in grams that can be formed?

2. ## Chemistry

A solution contains 1.50 g of dissolved Pb 2+ ions. How many grams of NaI must be added to the solution to completely precipitate all of the dissolved Pb 2+ as PbI2?

3. ## Chemistry

How many moles of O2 are needed for the complete combustion of 3 moles of CH4?

4. ## Math

Anita says the plus sign + forms 2 pairs of vetical angles. Charles says it forms 2 pairs of congruent angles? Who is correct, and why? Wouldn't it be both, because there are 2 pairs of opposite angles with the same measure, and 4 congruent angles.

5. ## Chemistry

how do I work out the molecular mass of a substance such as oxide of arsenic? If I'm trying to work out the oxide part of this problem, where does hydrogen come into it? You have to know the mass, and how many moles. There are other methods. Hydrogen?

6. ## Chemistry

if the yieeld for the following reaction is 85% how many grams of Al2S3 should be used to produce 165 g of Al(OH)3? Al2S3+6H2O-->2Al(OH)3+3H2S

7. ## Chemistry

A 1.8 mole sample of a compound weighs 195 g and is found to be 11.18% H and 88.82% C. What is the molecular formula for the compound?

8. ## Chemistry

I need to work out the density of the gaseous oxide of arsenic at STP in g L-1 I realise density = mass/volume but my answer works out very high!! I have already worked out the volume to be 52cm^3 (Cubed). the mass to start with was 0.702g and at the end

9. ## Chemistry

A sample of iron ore contains 1.02 x 10^24 Fe atoms and is found to be 69.94% Fe by mass. What is the mass of the sample?

10. ## math

Wayne will get \$4200 if his salary is increase by 20%.Wayne's salary is 40% less the barry.Find Barry's salary.

11. ## math

Wayne will get \$4200 if his salary is increase by 20%.Wayne's salary is 40% less the barry.Find Barry's salary.

12. ## Chemistry

How many atoms are there in a 15.0-g sample of KBr?

13. ## Chemistry

How many atoms are there in a 15.0-g sample of KBr?

14. ## Writing

Complete the phrase: You give me love, You gave me life. You give me shelter, You gave me __________.

1. ## Math algebra

If you have 6 cups of flour for pancakes and you have 2 cups of water

posted on September 11, 2016
2. ## life orientation

by introducing campaign like NGO

posted on April 27, 2016
3. ## chemistry

posted on April 24, 2012
4. ## chemistry

q=m*c*change of t m=mass c= specific heat change of t= final temp- initial temp fill in these with your numbers and you should get the answer

posted on April 24, 2012