PLEASEEE Chemistry help..the questions are about tpes of reactions..?

Question

1. What are the correct formulas of the products for this reaction:
Pb(NO3)2 + NaCl2--->

a. Ba(CO3) + K2Cl
b.PbCl + NaNO3
c.PbCl2 + NaNO3
d. PbCl3 + NaNO3

2. What are the correct formulas of the products for this reaction:
Al+Cl2--->

a. AlCl2
b. Al2Cl3
c. AlCl3
d. AlCl4

3. In a _____ reaction, two or more elements or compounds form one product.

a.double replacement
b. decomposition
c. combination
d. single replacement
e. combustion

4. The following reaction is an example of a _____ reaction.
2Na + Cl2g --> 2NaCl

a.decomposition
b. displacement
c. double replacement
d. single replacement
e. combination
5.
6. What coefficient should be in front of bromine (Br2) in the balanced equation for the following reaction?
CBr4 +BrO3 -->CO2 + Br2

a. 7
b. 6
c. 4
d. 3
7. Which is properly balanced and written correctly?
a. 2Na+ 4Cl2 -> 2NaCl
b. 2Na+2H2O-> 2NaOH+h2
c. 2HCl+ Mg -> 2MGCl2 +h2

Answer 1

You have to remember that there are 5 basic types of chemical reactions: synthesis/combination, combustion, decomposition, single replacement, and double replacement. Each one always follows the same general pattern, so you can predict what the products will be.

1. This is a double replacement reaction, because you're starting out with 2 compounds and a double replacement is the only thing that can really occur. In a double replacement, the two metals switch places with each other, so the correct answer would be C--PbCl2 + NaNO3. The lead and the sodium switched places.

2. This one is a synthesis (or combination) reaction. You know this because you're starting with 2 elements, and they have to combine to form a compound. Knowing this, it really shouldn't be all that hard to guess the compound--some kind of aluminum chloride, but you have to make sure the charges balance. Aluminum is +3 and chlorine is -1, so your formula is AlCl3.

3. C. Combination would be the correct answer. It's not all that hard to remember if you think about it logically; when you combine ingredients for cookies, you get one product--the cookies. It works the same way for a chemical reaction.

4. Think about it: you've got two elements combining to form one product. What kind of reaction is that?

6. To balance the equation, starting with oxygen would probably be the easiest way to go. If you put a 3 in front of the CO2 and a 2 in front of the BrO3, then you've balanced the oxygen.

CBr4 + 2BrO3 >>> 3CO2 + Br2

Now to balance the carbon. We have 3 carbon atoms on the right side, so we'll balance it by putting a 3 in front of the CBr4 on the left.

3CBr4 + 2BrO3 >>> 3CO2 + Br2

If you count up the number of bromine atoms you have on the left, you get 14. If you put a coefficient of 7 in front of the Br2, then your equation is balanced.

3CBr4 + 2BrO3 >>> 3CO2 + 7Br2

The correct answer for 6. is A. 7.

7. Check the number of atoms of each element on each side of the equation to see if it balances. For A., you have 8 Cl on the left side and only 2 on the right, so it isn't balanced. In C., you have 1 Mg on the left and 2 on the right, so that doesn't balance either. That must mean that B. is properly balanced. There are 2 atoms of Na on both sides, 4 atoms of H on both sides, and 2 atoms of O on both sides. B is the properly balanced equation.

Answer 2

1) c
2) c
3) c
4) e
6) coefficients for all of them need to be changed to be balanced
3CBr4 + 2BrO3 --> 3CO2 + 7Br2

7) b

Answer 3

1. C
2.C
3.C
4.E
5.whatever
6.i dont find the ans. sorry
7.B

Answer 4

do your own homework