Answer:

Explanation:
First reaction gives you the number of moles or the mass from Carbon and hydrogen
for carbon:


Analogously for hydrogen:
0.0310g
have 0.0034gH or 0.0034mol of H
In the second reaction you can obtain the amount of nitrogen as a percentage and find the mass of N in the first sample.

now

this is equivalet to 0.002mol of N
with this information you can find the mass of oxygen by matter conservation.

this is equivalent to 0.004molO
finally you divide all moles obtained between the smaller number of mole (this is mol of H)

and you can multiply by 5 to obtain: 
Answer:
Sry but i hope u will get the right answer and have a great christmas only 3 more days!
Explanation:
Answer:
The mass of 10 cm³of a 0.4 g/dm³ solution of sodium carbonate is 0.004 grams
Explanation:
The question is with regards to density calculations
The density of the given sodium carbonate solution, ρ = 0.4 g/dm³
The volume of the given solution of sodium carbonate, V = 10 cm³ = 0.01 dm³


Therefore, we have;

The mass, "m", of the sodium carbonate in = ρ×V = 0.4 g/dm³ × 0.01 dm³ = 0.004 g
The mass of 10 cm³ (10 cm³ = 0.01 dm³) of a 0.4 g/dm³ solution of sodium carbonate, m = 0.004 g.
Three factors that affect magma viscosity are temperature, composition, and presence of dissolved gases.
You have to use the Henderson-Hasselbalch equation. Keep in mind that because the Pka is given the equation changes form slightly:
PH = Pka + log[acid/base]
Step 1 (Figure out the concentrations):
0.282 M of Acid (C6H5OOH) - 0.150 M = 0.132 M of acid
0.282 M of Base (C6HCOO) + 0.150 M = 0.432 M of bas3
Step 2 (Plug into equation):
PH = Pka + log[acid/base]
PH = 4.20 + log[0.132 M/0.432 M]
PH = 3.69