Answer:
= 67.79 g
Explanation:
The equation for the reaction is;
4Cr(s)+3O2(g)→2Cr2O3(s)
The mass of O2 is 21.4 g, therefore, we find the number of moles of O2;
moles O2 = 21.4 g / 32 g/mol
=0.669 moles
Using mole ratio, we get the moles of Cr2O3;
moles Cr2O3 = 0.669 x 2/3
=0.446 moles
but molar mass of Cr2O3 is 151.99 g/mol
Hence,
The mass Cr2O3 = 0.446 mol x 151.99 g/mol
<u> = 67.79 g
</u>
D milk turning sour
the other options are physical changes
Answer:
Explanation:
<u><em>What is the potential energy of a 2-kg book sitting on a shelf 2 meters above the ground?</em></u>
<em></em>
PE = MGH, that is, potential energy = mass x gravity x height.
2*2*9.8=
39.2 joules
