Answer:
Al 72.61%
Mg 27.39%
Explanation:
To obtain the mass percentages, we need to place the individual masses over the total mass and multiply by 100%.
If we observe clearly, we can see that the parameters given are the moles. We need to convert the moles to mass.
To do this ,we need to multiply the moles by the atomic masses. The atomic mass of aluminum is 27 while that of magnesium is 24.
Now, the mass of aluminum is thus = 27 * 0.0898 = 2.4246g
The mass of magnesium is 0.0381 * 24 = 0.9144g
We can now calculate the mass percentage.
The total mass is 0.9144 + 2.4246 = 3.339g
% mass of Al = 2.4246/3.339 * 100 = 72.61%
% mass of Mg = 0.9144/3.39 * 100 = 27.39%
Answer:
29 protons 29 electrons
34 neutrons or (65-29)=36 neutrons in its nucleus.
During this phase Change heat energy is being absorbed by the molecules, and as a result the molecules possess a greater ability to move around and possess higher kinetic energy because of this. The molecules also possess a higher potential energy.
<u>Answer:</u> The element represented by M is Strontium.
<u>Explanation:</u>
Let us consider the molar mass of metal be 'x'.
The molar mass of MO will be = Molar mass of oxygen + Molar mass of metal = (16 + x)g/mol
It is given in the question that 15.44% of oxygen is present in metal oxide. So, the equation becomes:
The metal atom having molar mass as 87.62/mol is Strontium.
Hence, the element represented by M is Strontium.
First calculate the moles of N2 and H2 reacted.
moles N2 = 27.7 g / (28 g/mol) = 0.9893 mol
moles H2 = 4.45 g / (2 g/mol) = 2.225 mol
We can see that N2 is the limiting reactant, therefore we
base our calculation from that.
Calculating for mass of N2H4 formed:
mass N2H4 = 0.9893 mol N2 * (1 mole N2H4 / 1 mole N2) * 32
g / mol * 0.775
<span>mass N2H4 = 24.53 grams</span>
