Answer:
56.69905
Explanation:
The conversion factor from pounds to kilograms is 0.45359237, which means that 1 pound is equal to 0.45359237 kilograms.
The matter of changes in volume is gas
Answer:
B) we will convert the 10 g of NaCl into moles.
Explanation:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
we will convert the 10 g of NaCl into moles.
Number of moles of NaCl:
Number of moles = mass/molar mass
Number of moles = 10 g/ 58.44 gmol
Number of moles = 0.17 mol
1 Kg = 1 L
Molarity = 0.17 mol / 2 L
Molarity = 0.085 mol/L
Molarity = 0.085 M
Answer:
3.99 g
Explanation:
The following data were obtained from the question:
Half life (t½) = 2 years.
Original amount (N₀) = 128 g
Time (t) = 10 years
Amount remaining (N) =..?
Next, we shall determine the rate of disintegration of the isotope. This can be obtained as follow:
Half life (t½) = 2 years.
Decay constant (K) =.?
K= 0.693/t½
K = 0.693/2
K = 0.3465 year¯¹.
Finally, we shall determine the amount remaining after 10 years i.e the amount remaining when they arrive on Earth. This can be obtained as follow:
Original amount (N₀) = 128 g
Time (t) = 10 years
Decay constant (K) = 0.3465 year¯¹.
Amount remaining (N) =..?
Log (N₀/N) = kt/2.3
Log (128/N) = (0.3465 × 10)/2.3
Log (128/N) = 1.5065
Take the antilog of 1.5065
128/N = Antilog (1.5065)
128/N = 32.1
Cross multiply
128 = 32.1 × N
Divide both side by 32.1
N = 128/32.1
N = 3.99 g
Therefore, the amount remaining is 3.99 g
The molality of the toluene is 1.46 mol/kg.
<h3>
What is molality?</h3>
The molality of a solution is its molal concentration. Molal concentration is denoted by m. It is the mol of solute dissolves in 1 Kg solvent.
The depression at freezing point is directly proportional to the molality of the solution. The equation we use for this type of problem is:
ΔT=iKm 
Where, ΔT is depression at freezing point, i is Van't hoff factor, m is molality and 
is the freezing point depression constant.
Toluene is a non-electrolyte and so the value of i for this is 1.
Depression at a freezing point is given as -13.
and the is given as 5.12. So, we could calculate the molality of the solution using the equation written above.
Let's plug in the values in the equation:
ΔT=iKm
-7.51 =1 x5. 12 xm
m = 
m = 1.46 m
It means the molality of the solution is 1.46 mol/kg.
Hence, the molality of the solution is 1.46 mol/kg.
Learn more about the molality of the solution here:
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