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3 years ago

(01.01 LC)

Chemistry

2 answers:

bogdanovich [222]3 years ago

8 0

Answer: Paid sponsorship by a company

Explanation:

A reliable science can be considered as the facts which can be proved and rectified by using efficient scientific experiments the data obtain from such processes are reliable and acceptable by the scientific community.

Among the options given, paid sponsorship by a company is the correct option this is because of the fact that if the company sponsors the tests which are required to prove the efficiency of the products then such results may be manipulated and unreliable.

Monica [59]3 years ago

5 0

Paid sponsorship by a company

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Explain what a chemical reaction is and moles

Delvig [45]

Answer:

A process during which chemical bonds between atoms are broken and new ones are formed, producing one or more substances.

Moles are the amount of substance that contains as many particles.

Explanation:

A chemical reaction is when a chemical change occurs for example when a nail comes into contact with air and is then exposed to air it begins to rust. It forms a red-brown substance which changes the chemical composition of the original compound.

Examples of chemical reactions:

Combustion

Oxidation (rusting)

Cooking an egg

Photosynthesis

Digestion

Fireworks

Paper Burnin

The mole is the amount of substance that contains as many particles (molecules, ions or atoms) as there are in 12g of carbon.

1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12 and that number is referred to as Avogardo's constant (6.022 x $10^{23}$ ).

3 0

2 years ago

You mix 285.0 mL of 1.20 M lead(II) nitrate with 300.0 mL of 1.60 M potassium iodide. The lead(II) iodide is insoluble. Which of

SIZIF [17.4K]

Answer:

D. The final concentration of NO3– is 0.821 M.

Explanation:

Considering:

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

Or,

$Moles =Molarity \times {Volume\ of\ the\ solution}$

Given :

For potassium iodide :

Molarity = 1.60 M

Volume = 300.0 mL

The conversion of mL to L is shown below:

1 mL = 10⁻³ L

Thus, volume = 300.0×10⁻³ L

Thus, moles of potassium iodide :

$Moles=1.60 \times {300.0\times 10^{-3}}\ moles$

Moles of potassium iodide = 0.48 moles

For lead(II) nitrate :

Molarity = 1.20 M

Volume = 285 mL

The conversion of mL to L is shown below:

1 mL = 10⁻³ L

Thus, volume = 285×10⁻³ L

Thus, moles of lead(II) nitrate :

$Moles=1.20\times {285\times 10^{-3}}\ moles$

Moles of lead(II) nitrate = 0.342 moles

According to the given reaction:

$2KI_{(aq)}+Pb(NO_3)_2_{(aq)}\rightarrow PbI_2_{(s)}+2KNO_3_{(aq)}$

2 moles of potassium iodide react with 1 mole of lead(II) nitrate

1 mole of potassium iodide react with 1/2 mole of lead(II) nitrate

0.48 moles potassium iodide react with 0.48/2 mole of lead(II) nitrate

Moles of lead(II) nitrate = 0.24 moles

Available moles of lead(II) nitrate = 0.342 moles

Limiting reagent is the one which is present in small amount. Thus, potassium iodide is limiting reagent.

Also, consumed lead(II) nitrate = 0.24 moles (lead ions precipitate with iodide ions)

Left over moles = 0.342 - 0.24 moles = 0.102 moles

Total volume = 300 + 285 mL = 585 mL = 0.585 L

So, Concentration = 0.102/0.585 M = 1.174 M

Statement A is correct.

The formation of the product is governed by the limiting reagent. So,

2 moles of potassium iodide gives 1 mole of lead(II) iodide

1 mole of potassium iodide gives 1/2 mole of lead(II) iodide

0.48 mole of potassium iodide gives 0.48/2 mole of lead(II) iodide

Mole of lead(II) iodide = 0.24 moles

Molar mass of lead(II) iodide = 461.01 g/mol

Mass of lead(II) chloride = Moles × Molar mass = 0.24 × 461.01 g = 111 g

Statement B is correct.

Potassium iodide is the limiting reagent. So all the potassium ion is with potassium nitrate . Thus,

2 moles of Potassium iodide on reaction forms 2 moles of potassium ion

0.48 moles of Potassium iodide on reaction forms 0.48 moles of potassium ion

Total volume = 300 + 285 mL = 585 mL = 0.585 L

So, Concentration = 0.48/0.585 M = 0.821 M

Statement C is correct.

Nitrate ions are furnished by lead(II) nitrate . So,

1 mole of lead(II) nitrate produces 2 moles of nitrate ions

0.342 mole of lead(II) nitrate produces 2*0.342 moles of nitrate ions

Moles of nitrate ions = 0.684 moles

So, Concentration = 0.684/0.585 M = 1.169 M

Statement D is incorrect.

4 0

3 years ago

What is the molar mass of Ca(NO3)2?

Valentin [98]

The answer to the molar mass of Ca(NO3)2 is gonna be C. 164.1 g/mol

3 0

3 years ago

Read 2 more answers

What is the theoretical yield of SO3 produced by 8.96 g of S?

Virty [35]

Answer: Theoretical yield of $SO_3$ produced by 8.96 g of S is 33.6 g

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$

$\text{Moles of} S=\frac{8.96g}{32g/mol}=0.28moles$

The balanced chemical equation is:

$2S+3O_2\rightarrow 2SO_3$

According to stoichiometry :

2 moles of $S$ produce = 3 moles of $SO_3$

Thus 0.28 moles of $S$ will produce= $\frac{3}{2}\times 0.28=0.42moles$ of $SO_3$

Mass of $SO_3=moles\times {\text {Molar mass}}=0.42moles\times 80g/mol=33.6g$

Thus theoretical yield of $SO_3$ produced by 8.96 g of S is 33.6 g

7 0

3 years ago

Why compounds with weak molecular forces are usually gases.

mihalych1998 [28]

Answer:

Intermolecular forces are much weaker than the strong covalent bonds within the molecules. ... Very little energy is needed to overcome the intermolecular forces, so simple molecular substances usually have low melting and boiling points. They are often liquids or gases at room temperature

8 0

2 years ago