# Recent content by Aya

1. ### Chemistry review questions-calculations

^ Oh, ok thanks for all your help!
2. ### Chemistry review questions-calculations

4. M=Mol/vol M= 0.2mol/2.0L M=0.1mol/L *** The teacher said we should only balance with whole nubbers so would it be 2H2 + O2 = 2H2O....? moles of H 0.22 mol sooo... moles of O is also 0.11mol? c)calculate the number of moles of water produced when 4.00 g of oxygen are used 2H2 + O2 = 2H2O...
3. ### Chemistry review questions-calculations

Hi, I have some reviw questions for the upcomming chemistry exam, the problem is I don't have the answers so can some one read throught my work and check if it is wright? Thanks. *** 1. An anaysis of a valitile liquid shoed that it wsa composed of 14.4%C, 2.37% H and 83.49% Cl. If 4.25 g of...
4. ### Pleas help! exam tommarow Trigonometry word problems

Pleas help! exam tommarow!!!! Trigonometry word problems Hi, i really need help with this question, on a wall, a spider is 100cm above a fly. the fly starts moving horizontally at the speed of 10cm/s. After 1s, the spider begins moving at twice the speed of the fly, in such a way as to...
5. ### Sequence and series word problem

Its supposed to be sequences and series so what I was doing was finding the % of medicnin that was in his body, but I guess this approach was wrong So I have to find the amount of medicin that is in his body So... t0=5oomg t1=625mg t2=656.25 Then tn-1 x 0.25+500 would be the recursave fomula
6. ### Sequence and series word problem

Tod injured his wrist while he was skateboarding. To relive the pain his doctor prescribed him some medication. He takes 500mg of medicine every 6h. Only 25 % of the medication remains in his body by the time he is ready to take another pill. Write and equation to model this. so 25% is...
7. ### Counting backwards; Sequences

1. are you sure? the answer in the back of the book sayes it is 34 and i cheked it again. _____________________________________________________________ 2. ok, thanks _______________________________________________________________ 4. the sum of 50 consecutive even intergers is 3250. tha...
8. ### Counting backwards; Sequences

Please help I have ALOT of questions!! 1.)Starting at 888 and counting backward by 7, a student counts 888, 881 and 874, and so on. Which of the following numbers will be included? a) 35 b) 34 c) 33 d) 32 e) 31 Ok, so I by using the calcuator the aswer is 34, but how would you calcuate...
9. ### Arithmetic series

^ ok, thanks for all your help
10. ### Arithmetic series

OK, these questions are supposed to be really easy, but I keep geting the wrong answer and I don't understand why, could someone pleas look at my work and tell me what I am doing wrong? Find the indicated sum of each arithmetic series S15 for 4 + 11 + 18 + ... Sn= n/2 [ 2a + ( n - 1 ) d...
11. ### Iron ore extraction

The cost of extracting and purifying metals is varied for various reasons, this means that the company might not make profit on the iron ore. Since there is a ,relatively, large amount of iron ore it is cheap. This means that the company needs to find a lot of it in order to make a profit. If...
12. ### Writing equations

so Fe2O3 + 3CO = 2Fe + 3CO2 Is this right?
13. ### Iron ore extraction

^ sorry I ment enviromental. Thanks for all your help!
14. ### Iron ore extraction

^ Ok thank you, so no marks taken off by saying there are no positive economic impacts if i explain..right?
15. ### Iron ore extraction

I really don't know what catagoir this would go under :confused: , but its an assignment for chem so... Woud there be any positive envromental impacts of iron ore extraction? This was on of the topics we had to reaserch, but form 3 days of searching throught the net, positive effects iron ore...