Explanation:
It is known that one mole of chromium or molar mass of chromium is 51.99 g/mol.
It is given that number of moles is 11.9 moles.
Therefore, calculate the mass of chromium in grams as follows.
No. of moles = 
mass in grams = No. of moles × Molar mass
= 11.9 moles × 51.99 g/mol
= 618.68 g
Thus, we can conclude that there are 618.68 g in 11.9 moles of chromium.
Organic compounds contain carbon
Answer:
89.34%
Explanation:
First, write a balanced reaction.
Mg3N2 + <u>6</u>H2O --> <u>3</u>Mg (OH)2 + <u>2</u>NH3
Next determine the moles of the known substance, or limiting reagent ( H2O)
n= m/MM
n ( H2O) = 4.33/(1.008×2)+16
n(H2O)= 0.2403
Use the mole ratio to find the moles of Mg(OH)2
0.2403 ÷2
n (Mg (OH)2) = 0.1202
Next, find the theoretical mass of Mg (OH)2 that should have been produced
m= n × MM
m= 0.1202 × (24.305 + (16×2) +(1.008 ×2))
=7.007g
To find percentage yield, divide the experimental amount by the theoretical amount and multiply by 100.
6.26/ 7.007 × 100
=89.34%
V = 75 mL = 0,075 L = 0,075 dm³
C = 2.1M
n = ?
---------------
C = n/V
n = C×V
n = 2.1×0,075
n = 0,1575 mol
--------
mKCl: 39+35.5 = 74,5 g/mol
74,5g --------- 1 mol
Xg ------------- 0,1575 mol
X = 74,5×0,1575
X = 11,73375g KCl
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