All categories

3 years ago

Why might it be important in a real life situation, to know if a chemical or physical change occurred?

1 answer:

6 0

There are four signs that a chemical reaction has occurred: a change in color, a change in temperature, formation of a gas or formation of a precipitate. A precipitate is a solid that forms when two liquid solutions are mixed. As matter changes in a chemical reaction, it can either absorb or release energy.

You might be interested in

A sample of vinegar was found to have an acetic acid concentration of 0.8846 m. What is the acetic acid % by mass? Assume the de

jenyasd209 [6]

Answer:

5.3%

Explanation:

Let the volume be 1 L

volume , V = 1 L

use:

number of mol,

n = Molarity * Volume

= 0.8846*1

= 0.8846 mol

Molar mass of CH3COOH,

MM = 2*MM(C) + 4*MM(H) + 2*MM(O)

= 2*12.01 + 4*1.008 + 2*16.0

= 60.052 g/mol

use:

mass of CH3COOH,

m = number of mol * molar mass

= 0.8846 mol * 60.05 g/mol

= 53.12 g

volume of solution = 1 L = 1000 mL

density of solution = 1.00 g/mL

Use:

mass of solution = density * volume

= 1.00 g/mL * 1000 mL

= 1000 g

Now use:

mass % of acetic acid = mass of acetic acid * 100 / mass of solution

= 53.12 * 100 / 1000

= 5.312 %

≅ 5.3%

3 0

3 years ago

Which of the following processes are physical changes? Mark all

stich3 [128]

The process that is physical changes is:

mixing frozen orange juice concentrate with water

<h3>What is a physical change?</h3>

A physical change can be described as a type of change that take place in physical without chemical reaction as opposed to chemical change.

They are changes that are usually reversible it should be noted that physical change do not involve the alterations as regards the chemical make up of a particular substance and as a result of this , in physical change, there is no formation of new product.

Therefore, The process that is physical changes is mixing frozen orange juice concentrate with water

Read more about physical changes here:

brainly.com/question/13056570

#SPJ1

7 0

2 years ago

The mass percentage of hydrochloric acid within a solution is 28.00%28.00% . Given that the density of this solution is 1.1411.1

sashaice [31]

Answer:

8.76M

Explanation:

Given that

Mass from the density = 1141g

According to the given situation the computation of molarity of the solution is shown below:-

we will took HCL solution which is 1000mL

HCl = 28% by mass

So,

Mass of HCl in 1-litre solution is

$= \frac{28}{100} \times 1141$

Which gives the result of molar mass HCI is

= 319.48g /mol

Now,

Molarity is

$= \frac{319.48}{36.45}$

Which gives results of molarity is

= 8.76M

8 0

3 years ago

How does heat move from one place to another on the troposphere

d1i1m1o1n [39]

I thinlk it's by radiation?......

8 0

4 years ago

Assume that you have a cylinder with a movable piston. What would happen to the gas pressure inside the cylinder if you do the f

pishuonlain [190]

Answer:

A. The pressure will increase 4 times. P₂ = 4 P₁

B. The pressure will decrease to half its value. P₂ = 0.5 P₁

C. The pressure will decrease to half its value. P₂ = 0.5 P₁

Explanation:

Initially, we have n₁ moles of a gas that occupy a volume V₁ at temperature T₁ and pressure P₁.

What would happen to the gas pressure inside the cylinder if you do the following?

Part A: Decrease the volume to one-fourth the original volume while holding the temperature constant. Express your answer in terms of the variable P initial.

V₂ = 0.25 V₁. According to Boyle's law,

P₁ . V₁ = P₂ . V₂

P₁ . V₁ = P₂ . 0.25 V₁

P₁ = P₂ . 0.25

P₂ = 4 P₁

Part B: Reduce the Kelvin temperature to half its original value while holding the volume constant. Express your answer in terms of the variable P initial.

T₂ = 0.5 T₁. According to Gay-Lussac's law,

$\frac{P_{1}}{T_{1}} =\frac{P_{2}}{T_{2}}\\\frac{P_{1}}{T_{1}} =\frac{P_{2}}{0.5T_{1}}\\\\P_{2}=0.5P_{1}$

Part C: Reduce the amount of gas to half while keeping the volume and temperature constant. Express your answer in terms of the variable P initial.

n₂ = 0.5 n₁.

P₁ in terms of the ideal gas equation is:

$P_{1}=\frac{n_{1}.R.T_{1}}{V_{1}}$

P₂ in terms of the ideal gas equation is:

$P_{2}=\frac{n_{2}.R.T_{1}}{V_{1}}=\frac{0.5n_{1}.R.T_{1}}{V_{1}}=0.5P_{1}$

3 0

3 years ago