Answer:
1.23 M
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of NaCl = 7.2 g
As we know , the molecular mass of NaCl = 58.5 g/mol
Moles is calculated as -
n = w / m = 7.2 g / 58.5 g/mol = 0.123 mol
Molarity is calculated as -
V = 100ml = 0.1 L (since , 1 ml = 1/1000L )
M = n / V = 0.123 mol / 0.1 L = 1.23 M
Answer:
35.8 g
Explanation:
Step 1: Given data
Mass of water: 63.5 g
Step 2: Calculate how many grams of KCl can be dissolved in 63.5. g of water at 80 °C
Solubility is the maximum amount of solute that can be dissolved in 100 g of solute at a specified temperature. The solubility of KCl at 80 °C is 56.3 g%g, that is, we can dissolve up to 56.3 g of KCl in 100 g of water.
63.5 g Water × 56.3 g KCl/100 g Water = 35.8 g KCl
Answer:
0.25 mole of H₂
Explanation:
The equation for the reaction is given below:
Mg + 2HCl —> MgCl₂ + H₂
From the question given above, we were told that the reaction produced 5.6 L of H₂.
Thus, we can obtain obtain the number of mole of H₂ that occupied 5.6 L at STP as follow:
1 mole of H₂ occupied 22.4 L at STP.
Therefore, Xmol of H₂ will occupy 5.6 L at STP i.e
Xmol of H₂ = 5.6 / 22.4
Xmol of H₂ = 0.25 mole
Therefore, 0.25 mole of H₂ were obtained from the reaction.
