Ba(CN) _ What is the compound

A student is instructed to make 1 L of a 2.0 M solution of CaCl2 using dry salt. How should he do this?

Pachacha [2.7K]

The student should follow following steps to make 1 L of 2.0 M CaCl₂.

1. First he should calculate the number of moles of 2.0 M CaCl₂ in 1 L solution.

Molarity of the solution = 2.0 M
Volume of solution which should be prepared = 1 L

Molarity = number of moles / volume of the solution

Hence, number of moles in 1 L = 2 mol

2. Find out the mass of dry CaCl₂ in 2 moles.

moles = mass / molar mass

Moles of CaCl₂ = 2 mol
Molar mass of CaCl₂ = 110.98 g/mol

Hence, mass of CaCl₂ = 2 mol x 110.98 g/mol
= 221.96 g

3. Weigh the mass accurately

4. Then take a cleaned and dry1 L volumetric flask and place a funnel top of it. Then carefully add the salt into the volumetric flask and finally wash the funnel and watch glass with de-ionized water. That water also should be added into the volumetric flask.

5. Then add some de-ionized water into the volumetric flask and swirl well until all salt are dissolved.

6. Then top up to mark of the volumetric flask carefully.

7. As the final step prepared solution should be labelled.

4 0

2 years ago

Write a molecular equation for the precipitation reaction that occurs (if any) when the following solutions are mixed. If no rea

iragen [17]

Answer :

(A) The balanced molecular equation will be:

$K_2CO_3(aq)+Pb(NO_3)_2(aq)\rightarrow 2KNO_3(aq)+PbCO_3(s)$

(B) The balanced molecular equation will be:

$Li_2SO_4(aq)+Pb(CH_3COOH)_2(aq)\rightarrow 2LiCH_3COOH(aq)+PbSO_4(s)$

(C) The balanced molecular equation will be:

$Cu(NO_3)_2(aq)+Na_2S(aq)\rightarrow 2NaNO_3(aq)+CuS(s)$

(D) The balanced molecular equation will be:

$Sr(NO_3)_2(aq)+2KI(aq)\rightarrow \text{No reaction}$

Explanation :

Molecular equation : It is defined as a balanced chemical equation where the ionic compounds are expressed in the form of molecules rather than component of ions.

Precipitation reaction : It is defined as the reaction in which an insoluble salt formed when two aqueous solutions are combined.

The insoluble salt that settle down in the solution is known an precipitate.

Part A : potassium carbonate and lead(II) nitrate

The balanced molecular equation will be:

$K_2CO_3(aq)+Pb(NO_3)_2(aq)\rightarrow 2KNO_3(aq)+PbCO_3(s)$

In this reaction, lead carbonate is an insoluble salt and potassium nitrate is a soluble solution.

Part B : lithium sulfate and lead(II) acetate

The balanced molecular equation will be:

$Li_2SO_4(aq)+Pb(CH_3COOH)_2(aq)\rightarrow 2LiCH_3COOH(aq)+PbSO_4(s)$

In this reaction, lead sulfate is an insoluble salt and lithium acetate is a soluble solution.

Part C : copper(II) nitrate and sodium sulfide

The balanced molecular equation will be:

$Cu(NO_3)_2(aq)+Na_2S(aq)\rightarrow 2NaNO_3(aq)+CuS(s)$

In this reaction, Cuprous sulfide is an insoluble salt and sodium nitrate is a soluble solution.

Part D : strontium nitrate and potassium iodide

The balanced molecular equation will be:

$Sr(NO_3)_2(aq)+2KI(aq)\rightarrow 2KNO_3(aq)+SrI_2(aq)$

In this reaction, strontium iodide and potassium nitrate are soluble solution.

$Sr(NO_3)_2(aq)+2KI(aq)\rightarrow \text{No reaction}$

6 0

3 years ago

Explore: Arrange the matter

Trava [24]

Answer:

The levels, from smallest to largest, are: molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere.

Explanation:

The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.

7 0

2 years ago

Read 2 more answers

How many moles of H20 are needed to produce 1 mole of O2 in the following equation?

Alex787 [66]

2 moles is the answer

6 0

3 years ago

Please help

Snezhnost [94]

Relatively few hydrogen atoms

5 0

3 years ago