I need help with these 2 chemistry questions please help me?

Question

1. ) Write the chemical formula for the following compounds nitrogen dioxide and diphosphorus pentaoxide.?

2.) What are the coefficients needed to balance the following equation? (No number in front of the compound is equal to 1):

MnO2 + NH4 --------> Mn2O3 + NH3 + H2O.

a. 1, 3-------> 4, 1, 2

b. 2, 1-------> 1, 2, 1

c. 2, 2 -------> 1, 2, 1

d. 2, 4--------> 1, 2, 1

Thank you for those who help.

Answer 1

It been a long time since chemistry so I don't remember #1 but the second answer is C

Answer 2

1.  To write chemical formulas from written names, it helps to know the Greek roots for the first few numbers:

1 - mono (or one is usually assumed if no prefix is given, some exceptions come in transition metal chemistry where the number of counter ions is determined from the oxidation state of the metal)

2 - di

3 - tri

4 - tetra

5 - penta

6 - hexa

7 - hepta

8 - octa

9 - nona

10 - deca

Using these roots, the chemical formulas are:

nitrogen dioxide = NO2

diphosphorus pentaoxide = P2O5

2.  Start with one atom and balance it first.  I like to look at the least common species in the reaction to start with (Mn in this case).

We have 2 Mn on the right side and only on on the left, so we need a 2 in front of MnO2.  This gives us four oxygens on the left side of the reaction and 4 oxygens on the right side, so oxygen is also balanced.

Now we look at our nitrogen, which balances, but hydrogen is not balanced (4 on left, 5 on right) so we need to adjust the NH4 and NH3 species to balance H.  Putting a 2 in front of each (systematic trial and error) gives us 2 nitrogens on each side and 8 hydrogens on each side, so our reaction is balanced.  Answer choice: c.

Hope this helps.

Answer 3

Geez, Chemistry was horrible when I took it. I was lucky to pass with a C... I wish I could help, but I could barely help myself

Answer 4

1) NO2 - nitrogen dioxide

    P2O5 - diphosphorus pentaoxide

2) solution: 2 MnO2 + 2 NH4 --------> Mn2O3 + 2 NH3 + H2O.

    answer: c. 2, 2 -------> 1, 2, 1