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3 years ago

Which of the following statements best describes why a chemical change is different from a physical change.

Chemistry

1 answer:

Butoxors [25]3 years ago

3 0

Answer:

C) Chemical changes involve formation of a new substance while physical change only impacts appearance or form.

Explanation:

The obvious difference between a chemical change and physical change is that in a chemical change new substances are produced while in a physical change, the form of the compounds are altered.

Most phase changes are products of physical changes. Such changes are easily reversible.
In a chemical change, a new kind of matter is formed. It is accompanied by energy changes.
The process is not easily reversible.

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Suppose you've just heard an opera singer warm up her voice. Write your own science question about the sounds a singer makes.

maxonik [38]

1. how does warming up help?
2. what does warming up do?
3. what would happen if you don’t warm up?

6 0

3 years ago

calculate the mass of calcium phosphate and the mass of sodium chloride that could be formed when a solution containing 12.00g o

Leviafan [203]

Answer : The mass of calcium phosphate and the mass of sodium chloride that formed could be, 9.3 and 10.5 grams respectively.

Explanation : Given,

Mass of $Na_3PO_4$ = 12.00 g

Mass of $CaCl_2$ = 10.0 g

Molar mass of $Na_3PO_4$ = 164 g/mol

Molar mass of $CaCl_2$ = 111 g/mol

Molar mass of $NaCl$ = 58.5 g/mol

Molar mass of $Ca_3(PO_4)_2$ = 310 g/mol

First we have to calculate the moles of $Na_3PO_4$ and $CaCl_2$ .

$\text{Moles of }Na_3PO_4=\frac{\text{Given mass }Na_3PO_4}{\text{Molar mass }Na_3PO_4}$

$\text{Moles of }Na_3PO_4=\frac{12.00g}{164g/mol}=0.0732mol$

and,

$\text{Moles of }CaCl_2=\frac{\text{Given mass }CaCl_2}{\text{Molar mass }CaCl_2}$

$\text{Moles of }CaCl_2=\frac{10.0g}{111g/mol}=0.0901mol$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is:

$2Na_3PO_4+3CaCl_2\rightarrow 6NaCl+Ca_3(PO_4)_2$

From the balanced reaction we conclude that

As, 3 mole of $CaCl_2$ react with 2 mole of $Na_3PO_4$

So, 0.0901 moles of $CaCl_2$ react with $\frac{2}{3}\times 0.0901=0.0601$ moles of $Na_3PO_4$

From this we conclude that, $Na_3PO_4$ is an excess reagent because the given moles are greater than the required moles and $CaCl_2$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $NaCl$ and $Ca_3(PO_4)_2$

From the reaction, we conclude that

As, 3 mole of $CaCl_2$ react to give 6 mole of $NaCl$

So, 0.0901 mole of $CaCl_2$ react to give $\frac{6}{3}\times 0.0901=0.1802$ mole of $NaCl$

and,

As, 3 mole of $CaCl_2$ react to give 1 mole of $Ca_3(PO_4)_2$

So, 0.0901 mole of $CaCl_2$ react to give $\frac{1}{3}\times 0.0901=0.030$ mole of $Ca_3(PO_4)_2$

Now we have to calculate the mass of $NaCl$ and $Ca_3(PO_4)_2$

$\text{ Mass of }NaCl=\text{ Moles of }NaCl\times \text{ Molar mass of }NaCl$

$\text{ Mass of }NaCl=(0.1802moles)\times (58.5g/mole)=10.5g$

and,

$\text{ Mass of }Ca_3(PO_4)_2=\text{ Moles of }Ca_3(PO_4)_2\times \text{ Molar mass of }Ca_3(PO_4)_2$

$\text{ Mass of }Ca_3(PO_4)_2=(0.030moles)\times (310g/mole)=9.3g$

Therefore, the mass of calcium phosphate and the mass of sodium chloride that formed could be, 9.3 and 10.5 grams respectively.

5 0

3 years ago

If you have an aqueous solution that contains 1.5 moles of hcl, how many moles of ions are in the solution? (a) 1.0, (b) 1.5, (c

Darya [45]

If you have an aqueous solution that contains 1.5 moles of HCl, the number of moles of ions in the solution is 3.0 moles.

<h2>Further Explanation </h2><h3>Strong acids </h3>

Strong acids are types of acids that undergo complete dissociation to form ions when dissolved in water.
Examples of such acids are, HCl, H2SO4 and HNO3
Dissociation of HCl

HCl + H₂O ⇔ H₃O⁺ + OH⁻

<h3>Weak acids </h3>

Weak acids are types of acids that undergo incomplete dissociation to form ions when dissolved in water.
Examples of such acids are acetic acids and formic acids.
Dissociation of acetic acid

H₃COOH ⇔ CH₃COO⁻ + H⁺; CH₃COO⁻ is a conjugate base of acetic acid.

HCl which is a strong acid that ionizes completely according to the equation;

HCl + H₂O ⇔ H₃O⁺ + OH⁻

From the equation, 1 mole of HCl produces 1 mole of H₃O⁺ ions and 1 mole of OH⁻ ions.

Therefore;

1.5 moles of HCl will produce;

= 1.5 moles of H₃O⁺ ions and 1.5 moles of OH⁻ ions.

This gives a total number ions of;

= 1.5 + 1.5

= 3 moles of ions

Keywords: Strong acid, weak acid, ions, ionization

<h3>Learn more about: </h3>

Strong acid: brainly.com/question/3239966
Weak acid; brainly.com/question/3239966
Ionization of acids and bases: brainly.com/question/11844503

Level: High school

Subject: Chemistry

Topic: Salts, Acids and Bases

6 0

3 years ago

Read 2 more answers

PLEASE HELP!!!

Elena L [17]

Answer:

no it should not that place is historical and so they should make where u can visit but protect it as a historical landmark

3 0

3 years ago

What is the mass of 0.28 mole of iron?

vredina [299]

Answer:

Your answer should be 15.68 grams.

Explanation:

Seeing as 1 mole has a mass of 56 g, 56*0.28 would get you 15.68 g.

6 0

3 years ago