Answer:
Calculate the mass percent of a potassium nitrate solution when 15.0 g KNO3 is dissolved in 250 g
of water.
2. Calculate the mass percent of a sodium nitrate solution when 150.0 g NaNO3 is dissolved in 500 mL
of water. Hint: 1 mL water = 1 g water
3. Calculate the weight of table salt needed to make 670 grams of a 4.00% solution.
4. How many grams of solute are in 2,200 grams of a 7.00% solution?
5. How many grams of sodium chloride are needed to prepare 6,000 grams of a 20% solution?
Mass Percent = Grams of Solute
Grams of Solution X 100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 26.8 grams NaCl
= 670 grams X 4.00%
100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 154 grams solute
= 2,200 grams X 7.00%
100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 1,200 grams NaCl
= 6,000 grams X 20.0%
100%
Explanation:
Sr(s)+Mg²+(aq)→Sr²+(aq)+Mg(s)
Number of e-'s transfered are, n=2. Equilibrium constant,
K=2.69×10∧12
ΔG=-2.303RT logK
R=gasconstant=8.314J/mol-k
T= temperature in K= 25 oC=25+273=298K
The value we get ΔG = -70922.3J. But ΔG = -nFE
n= number of e-'s transfered in the reaction =2
F= farady = 96500C
E=potential of the cell is what?
∴E = ΔG.nF
=-(-70922.3)/2×96500)
=0.367v.
Answer:
145 hours
Explanation:
Since one hour of riding a bicycle takes up 505 kcal of energy. It is also stated that one gram of body fat is equal to 7.70 kcal. Also, it is given that 1 pound of body fat is equal to 454 g.
Hence;
1 Ib= 454 g
21 Ib= 21 × 454/1 = 9534 g
But
1g of body fat = 7.70kcal
9534 g of body fat = 9534 × 7.70 kcal/1 = 73411.8 kcal
If 505 kcal is lost in 1 hour
73411.8 kcal is lost in 73411.8 kcal × 1hour/505k cal = 145 hours
The question is incomplete, the complete question is shown in the image attached.
Answer:
Cation
Explanation:
In a polar reaction mechanism, a specie must give out electrons and another specie must accept those electrons.
The specie that gives out electrons becomes electron deficient and positively charged so we refer to such a specie as a cation.
Hence, the specie that looses electrons becomes a cation.