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2 years ago

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Chemistry

1 answer:

Mrrafil [7]2 years ago

5 0

Answer:....................................

Explanation:

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Which element(s) is/are not balanced in this equation? <br> Pb(NO3)2 +2 Kcl -> pbCl2 + KNO3

UkoKoshka [18]

Answer:

The correct answer is KNO3

Explanation:

Pb(NO3)2 +2 KCl -> PbCl2 + KNO3

If we look at the left side of the equation we could see that there are 1 lead atom, 2 nitrate atoms ,2 potassium atoms and 2 chlorine atoms

Now when we look at the right side of the equation, we found that there are –

1 lead atom and 2 chlorine atoms (PbCl2) , thus lead and chlorine are balanced as they have the same number of atom in LHS and RHS

There is only 1 potassium and 1 nitrate atom on RHS , thus KNO3 is not balanced.

The balanced equation would be –

Pb(NO3)2 +2 KCl -> PbCl2 +2 KNO3

4 0

3 years ago

Read 2 more answers

A 20.7167 g sample of impure magnesium carbonate was heated to complete decomposition according to the equation mgco3(s) → mgo(s

marishachu [46]

The mass of impure $MgCO_{3}$ is 20.7167 g. The decomposition reaction is as follows:

$MgCO_{3}(s)\rightarrow MgO(s)+CO_{2}(g)$

Here, 1 mole of $MgCO_{3}$ gives 1 mole of MgO.

Molar mass of $MgCO_{3}$ and MgO is 84.31 g/mol and 40.3044 g/mol respectively.

Converting number of moles in terms of mass,

$n=\frac{m}{M}$

Here, M is molar mass.

Since, $n_{MgCO_{3}}=n_{MgO}$

Thus, $\frac{m_{MgCO_{3}}}{M_{MgCO_{3}}}=\frac{m_{MgO}}{M_{MgO}}$

On putting the values,

$\frac{m_{MgCO_{3}}}{84.31}=\frac{m_{MgO}}{40.3044}$

Rearranging,

$m_{MgO}=\frac{m_{MgCO_{3}}}{84.31}\times 40.3044$

Or,

$m_{MgCO_{3}}=\frac{m_{MgO}}{0.4780}$ ...... (1)

Let the mass of impurity be $M_{I}$ and mass of impure $MgCO_{3}$ is 20.7167 g thus,

$M_{MgCO_{3}}=(20.7167-M_{I})g$ ...... (2)

Also, mass of impure MgO is 16.8817 g thus,

$M_{MgO}=(16.8817-M_{I})g$ ...... (3)

On comparing equations (2) and (3),

$M_{MgO}=M_{MgCO_{3}}-3.835$

Putting the value of $M_{MgO}$ in equation (1),

$m_{MgCO_{3}}=\frac{M_{MgCO_{3}}-3.835}{0.4780}$

Or,

$0.4780 M_{MgCO_{3}}=M_{MgCO_{3}}-3.835$

Or,

$M_{MgCO_{3}}-0.4780M_{MgCO_{3}}=3.835$

Or,

$0.522 M_{MgCO_{3}}=3.835$

Or,

$M_{MgCO_{3}}=\frac{3.835}{0.522}=7.35 g$

Thus, magnesium carbonate present in the original sample is 7.35 g.

5 0

3 years ago

Phosphorus trichloride is used in the production of chemicals that keep plants from growing in a specific area. This

algol [13]

Answer: Hydrogen and oxygen make up water, which is a covalent compound. ... Phosphorus trichloride is used in the production of chemicals that keep plants from ... to Laura, the compound with the chemical name phosphorus trichloride has one atom of ... symbol P and three chlorine atoms represented by the chemical symbol Cl.

Explanation:

6 0

3 years ago

Read 2 more answers

Find the "natural" equilibrium concentration of NO in air in units of molecules/cm3 .

Vedmedyk [2.9K]

Answer:

6400 molecules / cm^3

Explanation:

10.6*10^-16 mol/L * 6.022*10^23 molecules/mol * 1 L / 1000 cm^3 * 1 / 100 L = 6400 molecules / cm^3

6 0

2 years ago

5 Boron has two types of atom, shown below.

Misha Larkins [42]

Explanation:

1. atom B has more neutrons than atom A

2. the name for this is Isotopes

3.atom A is lighter

8 0

3 years ago