Answer these two questions, please.

The columns in the periodic table are called groups. What do the elements in group 17 have in common?

natita [175]

Answer:

All of the elements in group 17 all have 7 valence electrons. This is one thing they all share in common.

Explanation:

7 0

3 years ago

Find how many milliliters of NaOH should be used to reach the half-equivalence point during the titration of 20.00 mL 0.888 M bu

Varvara68 [4.7K]

Answer: The volume of NaOH solution required to reach the half-equivalence point is 0.09 mL

Explanation:

The chemical equation for the dissociation of butanoic acid follows:

$CH_3CH_2CH_2COOH\rightleftharpoons CH_3CH_2CH_2COO^-+H^+$

The expression of $K_a$ for above equation follows:

$K_a=\frac{[CH_3CH_2CH_2COO^-][H^+]}{[CH_3CH_2CH_2COOH]}$

We are given:

$[CH_3CH_2CH_2COOH]=0.888M\\K_a=1.54\times 10^{-5}$

$[CH_3CH_2CH_2COO^-]=[H^+]$

Putting values in above expression, we get:

$1.54\times 10^{-5}=\frac{[H^+]^2}{0.888}$

$[H^+]=-0.0037,0.0037$

Neglecting the negative value because concentration cannot be negative

To calculate the volume of base, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is butanoic acid

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=1\\M_1=\frac{0.0037}{2}M\text{ (half equivalence)}\\V_1=20.00mL\\n_2=1\\M_2=0.425M\\V_2=?mL$

Putting values in above equation, we get:

$1\times \frac{0.0037}{2}\times 20.00=1\times 0.425\times V_2\\\\V_2=\frac{1\times 0.0037\times 20}{1\times 0.425\times 2}=0.087mL$

Hence, the volume of NaOH solution required to reach the half-equivalence point is 0.09 mL

5 0

3 years ago

Will give brainliest!!!!

butalik [34]

According to the law of conservation of mass, the mass of reactants will be equal to the mass of the products. The mass of products and reactants will only differ during a nuckear reaction
Changing of the physical state of water is not a nuclear reaction. So becoz of that the mass will remain constant without any change.

3 0

3 years ago

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You need to go through a closed door to escape a fire. which action should you take?

Alisiya [41]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.

If you need to go through a closed door to escape a fire the action that you should take is letter B or feel the door first using the back of your hand.

6 0

3 years ago

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Which of these solutes raises the boiling point of water the most?

Vlad [161]

I think the answer would be Ionic sodium phosphate (Na3PO4) because it has the greatest boiling point elevation.

7 0

3 years ago

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