Answer:
50000ppm and 0.855M.
Explanation:
ppm is an unit of chemistry defined as the ratio between mg of solute (NaCl) and Liters of solution. Molarity, M, is the ratio between moles of NaCl and liters
A 5% (w/v) NaCl contains 5g of NaCl in 100mL of solution.
To solve the ppm of this solution we need to find the mg of NaCl and the L of solution:
<em>mg NaCl:</em>
5g * (1000mg / 1g) = 5000mg
<em>L Solution:</em>
100mL * (1L / 1000mL) = 0.100L
ppm:
5000mg / 0.100L = 50000ppm
To find molarity we need to obtain the moles of NaCl in 5g using its molar mass:
5g * (1mol / 58.5g) = 0.0855moles NaCl
Molarity:
0.0855mol NaCl / 0.100L = 0.855M
Answer:
After the solution is heated, but before additional solute is added
Explanation:
An unsaturated solution is a solution that contains less solute than it can normally hold at a given temperature. Hence an unsaturated solution can still dissolve more solute.
When the solution is heated, the saturated cold solution becomes an unsaturated hot solution which is capable of dissolving more solute at this point.
Once more solute is dissolved, the solution becomes saturated again just before it begins to cool since no more solute dissolves in the solution at some point before cooling and addition of seed crystals.
Answer:
3.824 atm
Explanation:
From the ideal gas equation
P = mRT/MW × V
m is mass of testosterone = 12.9 g
R is gas constant = 82.057 cm^3.atm/mol.K
T is temperature of benzene solution = 298 K
MW is molecular weight of testosterone = 288.40 g/mol
V is volume of benzene solution = 286 ml = 286 cm^3
P = 12.9×82.057×298/288.4×286 = 3.824 atm
Answer:
Equation: - 2Li + H2O = Li2O + H2 Uncoated lithium metal reacts with water to form a colorless lithium hydroxide solution and hydrogen gas.
Explanation:
Answer:
A. 266g/mol
Explanation:
A colligative property of matter is freezing point depression. The formula is:
ΔT = i×Kf×m <em>(1)</em>
Where:
ΔT is change in temperature (0°C - -0,14°C = 0,14°C)i is Van't Hoff factor (1 for a nonelectrolyte dissolved in water), kf is freezing point molar constant of solvent (1,86°Cm⁻¹) and m is molality of the solution (moles of solute per kg of solution). The mass of the solution is 816,0g
Replacing in (1):
0,14°C = 1×1,86°Cm⁻¹× mol Solute / 0,816kg
<em>0,0614 = mol of solute</em>.
As molar mass is defined as grams per mole of substance and the compound weights 16,0g:
16,0g / 0,0614 mol = 261 g/mol ≈ <em>A. 266g/mol</em>
I hope it helps!
