All categories

3 years ago

How many grams of lithium sulfide must be dissolved in 1600.0 g water to make a 2.0 molal solution?

1 answer:

7 0

Molality is the number of moles of solutes in 1 kg of solvent.
the molality of solution to be prepared is 2.0 molal.
therefore 2 moles in 1 kg water.
the mass of Li₂S required is - 46 g/mol x 2.0 mol = 92 g
the mass in 1 kg of solvent is - 92 g
Therefore mass of Li₂S required in 1600.0 g is - 92 g/kg x 1.6 kg = 147.2 g

You might be interested in

The concentration of copper(II) sulfate in one brand of soluble plant fertilizer is 0.070% by weight. If a 21.5 g sample of this

Semmy [17]

Answer:

The molar concentration of $Cu^{2+}$ ions in the given amount of sample is $4.73\times 10^{-5}M$

Explanation:

Given that,

Mass of sample = 21.5 g

0.07 % (m/m) of copper (II) sulfate in plant fertilizer

This means that, in 100 g of plant fertilizer, 0.07 g of copper (II) sulfate is present

So, in 20 g of plant fertilizer

, $=\frac{0.07}{100}\times 21.5}\\=0.0151g$ of copper (II) sulfate is present.

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution (in L)}}$

Mass of solute (copper (II) sulfate) = 0.0151 g

Molar mass of copper (II) sulfate = 159.6 g/mol

Volume of solution = 2.0 L

$\text{Molarity of solution}=\frac{0.0151g}{159.6g/mol\times 2.0L}\\\\\text{Molarity of solution}=4.73\times 10^{-5}M$

The chemical equation for the ionization of copper (II) sulfate follows:

$CuSO_4\rightarrow Cu^{2+}+SO_4^{2-}$

1 mole of copper (II) sulfate produces 1 mole of copper (II) ions and sulfate ions

Molarity of copper (II) ions = $4.73\times 10^{-5}M$

Hence, the molar concentration of $Cu^{2+}$ ions in the given amount of sample is $4.73\times 10^{-5}M$

4 0

3 years ago

Please answer this question for 10 points

Dmitry_Shevchenko [17]

Is A have a nice day good luck b

4 0

3 years ago

Read 2 more answers

What is H20 and oxygen

olga2289 [7]

H2O means water, which is made of two hydrogen and one oxygen atoms.
Oxygen is a gas that your body needs to function. Oxygen comes from the air.

4 0

3 years ago

Read 2 more answers

3. 25. The temperatures favorable for the growth of most bacteria are

kvasek [131]

about the same as for humans

Explanation:

This is why most bacteria, during research in labs, are incubated at 37 degrees centigrade, about the same as human body temperature. In addition, harmful and beneficial bacteria thrive in the human body due to the favorable temperatures for growth and reproduction. To try and fight an infection, the body also tries to raise the body temperatures above the optimal for the bacteria growth (the reason one has a fever in case of infection).

6 0

3 years ago

Explain how the skeletal and muscular system work together to support body movement from this picture.

cricket20 [7]

Answer:

Tendons connect the skeletal system to the muscular system by attaching muscle to bone. When muscle contracts, the tendon acts on the bone, causing movement. Joints, the point at which two or more bones connect, can be fixed, slightly movable, or freely movable.

3 0

3 years ago