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3 years ago

If someone takes a material that looks pure, and then they do something to it that results

Chemistry

1 answer:

Sati [7]3 years ago

7 0

Answer:

The determination of the nature of the combination of the two separate materials in the original material that looks pure is based on the characteristic of the change process they undergo to become two separate materials.

Therefore, they can know if they initially had a mixture or a compound by the following steps;

1) If the two separated materials can be easily remixed to form the original material, then they likely have a mixture of the two separate materials

2) If the process that results in the formation of the two separate materials, involves the absorption or evolves heat or other forms of energy, then the original substance was a compound

3) If the two newly formed materials is seen to be a permanent change, then the original material was a compound

Explanation:

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What volume of nitrogen dioxide is formed at 735 torr and 28.2 °C by reacting 3.56 cm3 of copper (d = 8.95 g/cm3) with 200 mL of

weqwewe [10]

Answer:

25.76 L

Explanation:

Given, Volume of Copper = 3.56 cm³

Density = 8.95 g/cm³

Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

So,

So, Mass= Density * Volume = 8.95 g/cm³ * 3.56 cm³ = 31.862 g

Mass of copper = 31.862 g

Molar mass of copper = 63.546 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{31.862\ g}{63.546\ g/mol}$

Moles of copper = 0.5014 moles

Given, Volume of nitric acid solution = 200 mL = 200 cm³

Density = 1.42 g/cm³

Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

So,

So, Mass= Density * Volume = 1.42 g/cm³ * 200 cm³ = 284 g

Also, Nitric acid is 68.0 % by mass. So,

Mass of nitric acid = $\frac {68}{100}\times 284\ g$ = 193.12 g

Molar mass of nitric acid = 63.01 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{193.12\ g}{63.01\ g/mol}$

Moles of nitric acid = 3.0649 moles

According to the reaction,

$Cu_{(s)}+4HNO_3_{(aq)}\rightarrow Cu(NO_3)_2_{(aq)} + 2NO_2_{(g)} + 2H_2O_{(l)}$

1 mole of copper react with 4 moles of nitric acid

Thus,

0.5014 moles of copper react with 4*0.5014 moles of nitric acid

Moles of nitric acid required = 2.0056 moles

Available moles of nitric acid = 3.0649 moles

Limiting reagent is the one which is present in small amount. Thus, nitric acid is present in large amount, copper is the limiting reagent.

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

1 mole of copper on reaction forms 2 moles of nitrogen dioxide

So,

0.5014 mole of copper on reaction forms 2*0.5014 moles of nitrogen dioxide

Moles of nitrogen dioxide = 1.0028 moles

Given:

Pressure = 735 torr

The conversion of P(torr) to P(atm) is shown below:

$P(torr)=\frac {1}{760}\times P(atm)$

So,

Pressure = 735 / 760 atm = 0.9632 atm

Temperature = 28.2 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T₁ = (28.2 + 273.15) K = 301.35 K

Using ideal gas equation as:

PV=nRT

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

0.9632 atm × V = 1.0028 mol × 0.0821 L.atm/K.mol × 301.35 K

⇒V = 25.76 L

4 0

2 years ago

Iron(II) sulfide reacts with hydrochloric acid according to the reaction:

Inessa [10]

The balanced chemical reaction would be:

FeS(s)+2HCl(aq)→FeCl2(s)+H2S(g)

We are given the amount of the reactants to be used for the reaction. We use these amounts. First, we determine the limiting reactant of the reaction. From the data, we can say that FeS is the limiting ad HCl is the excess reactant. We calculate as follows:

Amount of HCl used: 0.240 mol FeS x 2 mol HCl / 1 mol FeS = 0.48 mol HCl

0.646 - 0.48 = 0.166 mol HCl left

8 0

2 years ago

Read 2 more answers

What’s the most density thing out of

Oksanka [162]

Answer:

Iron is the densest out of the given options.

Explanation:

Oxygen

1.429 g/L

Water

1000 g/L

Hydrogen Peroxide

1450 g/L

Iron

7874 g/L

Iron Oxide

5240 g/L

7 0

3 years ago

Which element has a smaller ionic radius than magnesium (Mg)?

barxatty [35]

Answer:

Na has atomic number 11

which is less than magnesium has atomic number 12

ANSWER IS D

Explanation:

aluminum or Al is atomic 13 and Ca or calcium is atomic number 20 and rubidium or Rb is atomic number 37

6 0

3 years ago

Is it possible to make new water

alexandr1967 [171]

No, Matter cannot be created nor deastroyed.

5 0

2 years ago

Read 2 more answers