Answer:
C = 18.29 g
Explanation:
Given data:
Mass of beryllium needed = ?
Mass of nitrogen = 18.9 g
Solution:
Chemical equation:
3Be + N₂ → Be₃N₂
now we will calculate the number of moles of nitrogen:
Number of moles = mass/molar mass
Number of moles = 18.9 g/ 28 g/mol
Number of moles = 0.675 mol
Now we will compare the moles of nitrogen and Be from balance chemical equation.
N₂ : Be
1 : 3
0.675 : 3/1×0.675 = 2.03 mol
Number of moles of Be needed are 2.03 mol.
Mass of Beryllium:
Mass = number of moles × molar mass
Mass = 2.03 mol × 9.01 g/mol
Mass = 18.29 g
I have posted the answetr in this picture.
Answer:
composed of two or more parts, elements, or ingredients:
Explanation:
Answer is: a beaker contains <span>
heterogeneous mixture.
</span>
A heterogeneous mixture<span> have compounds that remain separate in the sample.</span>
Heterogeneous
mixture is not uniform in composition (in this mixture different sand and small pebbles), but proportions of its components (in this
mixture particles of different colors and size) vary throughout
the sample.
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.
