Answer:
17.55 g of NaCl
Explanation:
The following data were obtained from the question:
Molarity = 3 M
Volume = 100.0 mL
Mass of NaCl =..?
Next, we shall convert 100.0 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
100 mL = 100/1000
100 mL = 0.1 L
Therefore, 100 mL is equivalent to 0.1 L.
Next, we shall determine the number of mole NaCl in the solution. This can be obtained as follow:
Molarity = 3 M
Volume = 0.1 L
Mole of NaCl =?
Molarity = mole /Volume
3 = mole of NaCl /0.1
Cross multiply
Mole of NaCl = 3 × 0.1
Mole of NaCl = 0.3 mole
Finally, we determine the mass of NaCl required to prepare the solution as follow:
Mole of NaCl = 0.3 mole
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mass of NaCl =?
Mole = mass /Molar mass
0.3 = mass of NaCl /58.5
Cross multiply
Mass of NaCl = 0.3 × 58.5
Mass of NaCl = 17.55 g
Therefore, 17.55 g of NaCl is needed to prepare the solution.
Answer:
Rate = k . [B]² . [C]
Explanation:
The dependence of the reaction rate on the concentration of the reactants is given by the reaction order of each one, as shown in the rate equation.
where,
k is the rate constant
x, y, z are the reaction orders.
- <em>The rate of reaction is not affected by changing the concentration of species A.</em> This means that the reaction order for A is x = 0 since when its concentration changes, the rate stays the same.
- <em>Leaving all other factors identical, doubling the concentration of species B increases the rate by a factor of 4.</em> This means that the reaction order for B is y = 2, so when the concentration is doubled, the new rate is 2² = 4 times the initial rate.
- The rate of the reaction is linearly dependent on the concentration of C. This means that the reaction order for C is z = 1, that is, a linear dependence.
All in all, the rate equation is:
Rate = k . [B]² . [C]