Answer:
Element Name & Symbol: Helium, He
Element Family : Noble Gasses
Atomic Number: 2
Atomic Mass: 4
Answer from Gauthmath
Explanation:
Assuming that moles of nitrogen present are 0.227 and moles of hydrogen are 0.681. And, initially there are 0.908 moles of gas particles.
This means that, for 
moles of 
+ moles of 
= 0.908 mol
Since, 2 moles of = 
= 0.454 mol
As it is known that the ideal gas equation is PV = nRT
And, as the temperature and volume were kept constant, so we can write
= 
= 
= 
= 5.2 atm
Therefore, we can conclude that the expected pressure after the reaction was completed is 5.2 atm.
Answer:
Mass of Na₂CrO₄ = 5.75 g
Explanation:
First of all we will write the balance chemical equation.
2AgNO₃ + Na₂CrO₄ → Ag₂CrO₄ + 2NaNO₃
Now we will calculate the moles of AgNO₃.
Number of moles = mass / molar mass
Molar mass of AgNO₃ = 107.87 + 14 + 3× 16 = 169.87 g/mol
Number of moles = mass / molar mass
Number of moles = 12.1 g / 169.87 g/mol = 0.071 mol
Now we will compare the moles of AgNO₃ and Na₂CrO₄ from balance chemical equation.
AgNO₃ : Na₂CrO₄
2 : 1
0.071 : 1/2× 0.071 = 0.0355
Now we will calculate the mass of Na₂CrO₄.
Molar mass of Na₂CrO₄ = 23×2 + 52 + 16×4 = 162 g/mol
Mass of Na₂CrO₄ = number of moles × molar mass
Mass of Na₂CrO₄ = 0.0355 mol × 162 g/mol
Mass of Na₂CrO₄ = 5.75 g
Answer:
1.5 moles of Ca²⁺ and 3 moles of NO₃⁻
Explanation:
This is the dissociation:
Ca(NO₃)₂ → Ca²⁺ + 2NO₃⁻
1.5 moles of salt will have the same moles of ion Ca²⁺ and the double of moles, of nitrate according to the equation.
Therefore will be 1.5 moles of Ca²⁺ and 3 moles of NO₃⁻
If its oxidised, water and carbon dioxide is formed.
