Answer:
-1.82 °C
Explanation:
Step 1: Given data
- Mass of NaCl (solute): 33.9 g
- Mass of water (solvent): 578 g = 0.578 kg
- Freezing point depression constant for water (Kb): -1.82 °C/m
Step 2: Calculate the molality of the solution
We will use the following expression.
m = mass of solute / molar mass of solute × kg of solvent
m = 33.9 g / 58.44 g/mol × 0.578 kg
m = 1.00 m
Step 3: Calculate the freezing point depression (ΔT)
The freezing point depression is a colligative property that, for a non-dissociated solute, can be calculated using the following expression:
ΔT = Kb × m
ΔT = -1.82 °C/m × 1.00 m
ΔT = -1.82 °C
Atomic mass Boron ( B ) = 10.811 u.m.a
10.811 g -------------- 6.02x10²³ atoms
5.40 g ----------------- ?? atoms
5.40 x ( 6.02x10²³) / 10.811 =
3.0069x10²³ atoms
Answer:
The answer to your question is 0.41 moles
Explanation:
Data
moles of NaCl = ?
mass of NaCl = 24 g
Process
To solve this problem just calculate the molar mass of NaCl, and remember that the molar mass of any substance equals to 1 mol.
1.- Calculate the molar mass
NaCl = 23 + 35.5 = 58.5 g
2.- Use proportions and cross multiplication
58.5 g of NaCl ------------------- 1 mol
24.0 g ------------------- x
x = (24 x 1) / 58.5
x = 0.41 moles
Answer:
0.38 moles KCl
Explanation:
(28 g KCl) / (74.55 g/mol KCl) = 0.38 moles KCl
Answer:
magnesium+ hydrochloric acid is the reactants
Explanation:
the reactants are always in the left and the products are always in the right by
magnesium+hydrochloric acid ⇒ magnesium chloride + hydrogen
by combining magnesium and hydrochloric acid it produces magnesium chloride and hydrogen.
hope this helps..
