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3 years ago

(HELP FAST)Which of the following always changes when a substance undergoes a chemical change?

Chemistry

2 answers:

Lera25 [3.4K]3 years ago

7 0

I’m pretty sure it’s a

GrogVix [38]3 years ago

3 0

A- the change of matter

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the ph of a solution of HCl in water is found to be 2.50. what volume of water would you add to 1.00L of this solution to raise

morpeh [17]

Answer:

To raise the pH of the solution to 3.10 we have to add 2.34 L of water.

Explanation:

Given that the pH of the solution of HCl in water is 2.5. Here the solution’s pH is changing from 2.5 to 3.10 which means the acidic nature of the solution is decreasing here on dilution. $[H^+]$ ions contribute to a solution’s acidic nature and $[OH^-]$ contribute to a solution’s basic nature.

The equation connecting the concentration of $[H^+]$ and pH of a solution is pH= $-log[H^+]$

 $[H^+]= 10^(^-^p^H^)$ $[H^+]= 10^(^-^2^.^5^)=0.00316$ 

When the pH is $3.1 [H^+ ]= 10^(^-^3^.^1^)=0.000794$ 

On dilution the concentration of a solution decreases and volume increases.

 $M_1 V_1 = M_2 V_2$ 

 $0.00316 \times 1 = 0.000794 \times V_2$ 

 $V_2 = \frac{(0.00316 \times 1)}{0.000794} =3.24$ 

Volume of water to be added $=3.24-1$ 

 $=2.24L$ 

6 0

3 years ago

An acid containing the cooh group is called a carbo-oxy acid.

Alexandra [31]

Yes if a molecule with a COOH group is called a carboxylic acid.

hope that helps

4 0

4 years ago

What is the correct defination for carbon tetrachloride

V125BC [204]

B - CCL4

This is because it doesn't say Dicarbon or any of that sort, so Carbon is alone. This immediately eiminates the option of C.

A is incorrect as it has Chlorine first rather than Carbon, so that's also incorrect.

D is incorrect as 7 is hepta rather than tetra.

The list is as so;

Mono - 1; Di - 2; Tri - 3; Tetra - 4; Penta - 5; Hexa - 6; Hepta - 7; Octa - 8; Nona - 9; Deca - 10.

Hope this helps!

5 0

3 years ago

7. How does Doppler radar help to predict tornadoes earlier

Novay_Z [31]

Answer:

It can help in predicting when a storm is being formed in a nearby area.

3 0

3 years ago

Which compound would you expect to be least soluble in water? Explain.

Sophie [7]

Answer: a.CCl4 aka carbon tetrachloride

Explanation:

ionic compounds and polar molecules can be dissolved in water which is a polar solvent.

choice d (KF) is a salt (an ionic compound) and can be dissolved in water /(K+ and F- ions would be formed in water).

choice c (NH3 or ammonia) is a very polar molecule and thus can be dissolved in water(Hydrogen bonding).

choice b (CH3Cl) is slightly polar because the atoms surrounding the central carbon atom are different(3 H atoms and 1 chlorine atom) and can be dissolved in water(Dipole-dipole interaction).

choice a is nonpolar and cannot be dissolved in water.

4 0

3 years ago