tropicalstorm98 (tropicalstorm98) wrote in chemistree,
tropicalstorm98
tropicalstorm98
chemistree

Assignment # 3

Once agin I want to thank everyone here for their help on my last assignment. I got an 80. Now I need help for this very last assignment.


*Question 1
What is the maximum number of electrons that can fit into the 5f subshell?

6
14
8
10
18
5

I want to say 18 but i'm not sure.

*Question 2

What is the correct chemical formula (not name) for the ionic compound that forms between potassium and oxygen?

Is the answer KO?


*Question 3
What is the charge on the tin ion in the compound below?

SnO

-1
+3
-2
+1
-3
+2

Metal tend to lose electron correct? if so the answer is foing to be a positive charge, but I don't know which one.

*Question 4
What is the correct name of the compound below?

CuCO3

copper monocarbonate
copper(I) carbonate
copper carbonate
copper(II) carbonate
copper carbontrioxide


I'm really bad at these but, I'm leaning towards the first one cuz of the "mono"


*Question 5
Classify the reaction below.

Ti + 2Cl2 → TiCl4

combination
decomposition
combustion
single replacement
double replacement

I think Its a single replacement, because Ti didn't gain or lose anything. But...hmm...combination. i'm not sure about that one.

*Question 6
Use the reaction below to answer the following true/false question

Zn(s) + Fe2+(aq) → Fe(s) + Zn2+(aq)


The iron(II) ion is the reducing agent in this reaction

True/false?

true because iron gave electrons to copper

*Question 7
Aqueous solutions of which two reactants below will produce a precipitate when mixed?

CuSO4 and Pb(NO3)2
NH4Cl and BaCl2
K3PO4 and NaCl

I need some help with this one. I could figure it out possibly if i knew the charges of each one.


*Question 8
You must express your answer to the correct number of significant figures to receive any credit. Enter only the numerical answer.
Use the balanced equation below for the following calculation.
4Fe + 3O2 → 2Fe2O3

_____ moles of O2 are needed to react completely with 9.00 moles of Fe.

I want to say 48 because, before the reaction occurs Oxygen is, 3O2. and one mol of O is 16 so 6*16= 96. when the reaction occur, Oygen go from 3O2 to O3. and 16*3= 48. is this right or am I totally off. Please be blunt if you must.


*Question 9

Use the balanced thermochemical equation below to answer the following problem. Your answer must contain the correct number of significant figures and be rounded off correctly to receive any credit. Enter only the numerical answer.
N2 + 3H2 → 2NH3 + 22.0 kcal
The reaction of 155 grams of N2 produces ________ kcal of heat.

I am clueless on this one. i think I am supposed to divide 155 by 22 but i'm not sure. Help?

*Question 10

Your answer must contain the correct number of significant figures and be rounded off correctly to receive any credit. Enter only the numerical answer.
A sample of gas has a volume of 5.2 L at STP. This sample of gas will occupy _____ L when the pressure changes to 962 mmHg while the temperature remains constant.



If someone can tell me what gas law i should use: ( Boyle, Charles, Gay-Lussac ,etc) I can figure this out

Thank you all for the help.
Any is appreciated
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