Answer:
Explanation:
We're asked to calculate the number of atoms of
Ca
in
153
g Ca
.
What we must first do is convert the given mass of calcium to moles of calcium, using its molar mass (referring to a periodic table, this is
40.08
g
mol
):
153
g Ca
(
1
mol Ca
40.08
g Ca
)
=
3.82
mol Ca
Using Avogadro's number,
6.022
×
10
23
particles
mol
, we can calculate the number of atoms present:
3.82
mol Ca
(
6.022
×
10
23
atoms Ca
1
mol Ca
)
=
2.30
×
10
24
atoms Ca
Answer:
0.44 moles
Explanation:
Given that :
A mixture of water and graphite is heated to 600 K in a 1 L container. When the system comes to equilibrium it contains 0.17 mol of H2, 0.17 mol of CO, 0.74 mol of H2O, and some graphite.
The equilibrium constant ![K_c= \dfrac{[CO][H_2]}{[H_2O]}](https://tex.z-dn.net/?f=K_c%3D%20%20%5Cdfrac%7B%5BCO%5D%5BH_2%5D%7D%7B%5BH_2O%5D%7D)
The equilibrium constant ![K_c= \dfrac{(0.17 )(0.17)}{0.74}](https://tex.z-dn.net/?f=K_c%3D%20%20%5Cdfrac%7B%280.17%20%29%280.17%29%7D%7B0.74%7D)
The equilibrium constant ![K_c= 0.03905](https://tex.z-dn.net/?f=K_c%3D%20%200.03905)
Some O2 is added to the system and a spark is applied so that the H2 reacts completely with the O2.
The equation for the reaction is :
![H_2 + \dfrac{1}{2}O_2 \to H_2O \\ \\ 0.17 \ \ \ \ \ \ \ \ \ \to0.17](https://tex.z-dn.net/?f=H_2%20%2B%20%5Cdfrac%7B1%7D%7B2%7DO_2%20%5Cto%20H_2O%20%5C%5C%20%5C%5C%200.17%20%5C%20%5C%20%5C%20%5C%20%5C%20%20%5C%20%5C%20%5C%20%5C%20%5Cto0.17)
Total mole of water now = 0.74+0.17
Total mole of water now = 0.91 moles
Again:
![K_c= \dfrac{[CO][H_2]}{[H_2O]}](https://tex.z-dn.net/?f=K_c%3D%20%20%5Cdfrac%7B%5BCO%5D%5BH_2%5D%7D%7B%5BH_2O%5D%7D)
![0.03905 = \dfrac{[0.17+x][x]}{[0.91 -x]}](https://tex.z-dn.net/?f=0.03905%20%3D%20%20%5Cdfrac%7B%5B0.17%2Bx%5D%5Bx%5D%7D%7B%5B0.91%20-x%5D%7D)
0.03905(0.91 -x) = (0.17 +x)(x)
0.0355355 - 0.03905x = 0.17x + x²
0.0355355 +0.13095
x -x²
x² - 0.13095
x - 0.0355355 = 0
By using quadratic formula
x = 0.265 or x = -0.134
Going by the value with the positive integer; x = 0.265 moles
Total moles of CO in the flask when the system returns to equilibrium is :
= 0.17 + x
= 0.17 + 0.265
= 0.435 moles
=0.44 moles (to two significant figures)
Its obviously D like what are you stupid lol jk don’t take it to heart kid
Explanation:
a ...15 seconds×(3600 seconds hour)