Ask question

Ask question

All categories

2 years ago

9

Why is it useful to group elements based on the way they behave in chemical reactions?

1 answer:

Basile [38]2 years ago

8 0

<em>The elements in a group often look and behave similarly, because they have the same number of electrons in their outermost shell — the face they show to the world. Group 18 elements, on the far right side of the table, for example, have completely full outer shells and rarely participate in chemical reactions.</em>

<em />

<h2><em>Have a nice day </em></h2>

You might be interested in

MrRissso [65]

Answer:

true

Explanation:

the small car also has gravity making it heavy

8 0

3 years ago

Identify the type of reaction occurring based on the description

postnew [5]

Answer:double displacement

Explanation:I just did it

8 0

3 years ago

If a 95.27 mL sample of acetic acid (HC2H3O2) is titrated to the equivalence point with 79.06 mL of 0.113 M KOH, what is the pH

KATRIN_1 [288]

Answer:

8.73

Explanation:

The concentration of acetic acid can be determined as follows:

$M_1V_1 = M_2V_2\\(KOH) = (CH_3COOH)$

$M_{KOH}=0.113 M\\V_{KOH}=79.06 mL$

$V_{CH_3COOH}=95.27 \\\\M_{CH_3COOH)=?????$

$M_{CH3COOH} = \frac{M_{KOH}*V_{KOH}}{V_{CH_3COOH}}$

$M_{CH3COOH} = \frac{0.113*79.06}{95.27}$

$M_{CH3COOH} = 0.094 M$

Moles of $CH_3COOH$ = $95.27* 10^{-3}* 0.094$

=0.0090 moles

Moles of $KOH = 79.06*10^{-3}*0.113$

= 0.0090 moles

The equation for the reaction can be expressed as :

$CH_3COOH$ $+$ $KOH$ -----> $CH_3COO^{-}K^+$ $+$ $H_2O$

Concentration of $CH_3COO^{-$ ion = $\frac{0.0090}{Total volume (L)}$

= $\frac{0.0090}{(95.27+79.06)} *1000$

= 0.052 M

Hydrolysis of $CH_3COO^{-$ ion:

$CH_3COO^{-$ $+$ $H_2O$ -----> $CH_3COOH$ $+$ $OH^-$

$K = \frac{K_w}{K_a} = \frac{x*x}{0.052-x}$

⇒ $\frac{10^{-14}}{1.82*10^{-5}}= \frac{x*x}{0.052-x}$

= $0.5494*10^{-9}= \frac{x*x}{0.052-x}$

As K is so less, then x appears to be a very infinitesimal small number

0.052-x ≅ x

$0.5494*10^{-9}= \frac{x^2}{0.052}$

$x^2 = 0.5494*10^{-9}*0.052$

$x^2 = 0.286*10^{-10$

$x = \sqrt{0.286*10^{-10$

$x =0.535*10^{-5}M$

$[OH] = x =0.535*10^{-5}$

$pOH = -log[OH^-]$

$pOH = -log[0.535*10^{-5}]$

$pOH = 5.27$

pH = 14 - pOH

pH = 14 - 5.27

pH = 8.73

Hence, the pH of the titration mixture = 8.73

8 0

2 years ago

A firework exploding is an example of a (4 points) physical change chemical change phase change nuclear change

Irina-Kira [14]

A firework exploding is a chemical change as soon as you light the fuse the combustion reacts with the gunpowder.

I hope this helps, good luck!!!!

5 0

3 years ago

The pH pH scale for acidity is defined by pH = − log 10 [ H + ] pH=-log10[H+] where [ H + ] [H+]is the concentration of hydrogen

balu736 [363]

Answer:

2 51 × 10^-5mol/L

Explanation:

The concentration of hydrogen ions can be calculated using the formula below :

pH = -log [H+]

pH = 4.6

[H+] = ?

[H+] = Antilog (-4.6)

[H+] = 2 51 × 10^-5mol/L

7 0

3 years ago