Answer:
b. 760 g
Explanation:
The mass of the solution = 800 g
5% of NaCl by mass of the solution can be determined as follows;
5% of 800 = 
× 800
= 5 × 8
= 40 g
The mass of NaCl in the solution is 40 g.
The mass of water = mass of solution - mass of NaCl
= 800 - 40
= 760 g
Therefore, the mass of water required is 760 g.
Rust on a nail is a chemical change.
Ice melting IS a physical change. Ice is made of water, when you melt ice its still water. Just in a different physical state.
Answer:
0.00471 grams H₂O
Explanation:
To determine the mass, you need to use the following equation:
Q = mcΔT
In this equation,
-----> Q = energy/heat (J)
-----> m = mass (g)
-----> c = specific heat capacity (J/g°C)
-----> ΔT = temperature change (°C)
The specific heat capacity of water is 4182 J/g°C. You can plug the given values into the equation and simplify to isolate "c".
Q = 0.709 J c = 4182 J/g°C
m = ? g ΔT = 0.036 °C
Q = mcΔT <----- Equation
0.709 J = m(4182 J/g°C)(0.036 °C) <----- Insert values
0.709 J = m(150.552) <----- Multiply 4182 and 0.036
0.00471 = m <----- Divide both sides by 150.552
Answer:
9.80 g
Explanation:
The molecular mass of the atoms mentioned in the question is as follows -
S = 32 g / mol
F = 19 g / mol
The molecular mass of the compound , SF₆ = 32 + ( 6 * 19 ) = 146 g / mol
The mass of 6 F = 6 * 19 = 114 g /mol .
The percentage of F in the compound =
mass of 6 F / total mass of the compound * 100
Hence ,
The percentage of F in the compound = 114 g /mol / 146 g / mol * 100
78.08 %
Hence , from the question ,
In 12.56 g of the compound ,
The grams of F = 0.7808 * 12.56 = 9.80 g
