The cyanide is

A carbon atom has 4 valance electrons and nitrogen has 5. Below is a Lewis-dot-structure of cyanide.
:N≡C.
The carbon atom is still one electron short of having a full octet and so it will seize another electron from almost anything, making the cyanide ion negative and whatever it took the electron from it now positive.
Answer: 3.4 atm
Explanation:
Given that:
Volume of gas V = 5L
(since 1 liter = 1dm3
5L = 5dm3)
Temperature T = 0°C
Convert Celsius to Kelvin
(0°C + 273 = 273K)
Pressure P = ?
Number of moles of gas n = 0.75 moles
Note that Molar gas constant R is a constant with a value of 0.0821 atm dm3 K-1 mol-1
Then, apply ideal gas equation
pV = nRT
p x 5dm3 = 0.75 moles x (0.0821 atm dm3 K-1 mol-1 x 273K)
p x 5dm3 = 16.8 atm dm3
p = (16.8 atm dm3 / 5dm3)
p = 3.4 atm
Thus, a pressure of 3.4 atm is exerted by the gas.
C₅H₁₂ + 8O₂ = 5CO₂ + 6H₂O
5CO₂ - 10O
6H₂O - 6O
16O - 8O₂
8 moles of molecular oxygen are consumed
Answer:
The percent composition is 21% N, 6% H, 24% S and 49% O.
Explanation:
1st) The molar mass of (NH4)2SO4 is 132g/mol, and it represents the 100% of the mass composition.
In 1 mole of (NH4)2SO4, there are:
- 2 moles of N.
- 8 moles of H.
- 1 mole of S.
- 4 moles of O.
2nd) It is necessary to calculate the mass of each element, multiplying its molar mass by the number of moles:
- 2 moles of N (14g/mol) = 28g
- 8 moles of H (1g/mol) = 8g
- 1 mole of S (32g/mol) = 32g
- 4 moles of O (16g/mol) = 64g
3rd) With a mathematical rule of three we can calculate the percent composition of each element in the molecule of (NH4)2SO4:




In this case, we can calculate the percent composition of Oxygen by subtracting the other percentages, since the total must be 100%.
So, the percent composition is 21% N, 6% H, 24% S and 49% O.
Hey there!
Molar mass Na2SO4 = 142.04 g/mol
Number of moles:
n = m / mm
n = 25 / 142.04
n = 0.176 moles of Na2SO4
Therefore, use the Avogadro constant
1 mole Na2SO4 ------------------- 6.02x10²³ molecules
0.176 moles Na2SO4 ------------ molecules ??
0.176 x ( 6.02x10²³ ) / 1
=> 1.059x10²³ molecules of Na2SO4
hope this helps!