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erma4kov [3.2K]

2 years ago

13

Who proposed a periodic table that accommodated for the discovery of new elements?

1 answer:

NeX [460]2 years ago

3 0

I think William Ramsey

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Your chemistry lab partner is interested in studying how industrial chemicals can pollute the environment. What type of chemistr

Solnce55 [7]

Answer:

I would recommend them becoming an Analytical Chemist because Analytical Chemists examine and identify various elements and compounds to find out the composition, structure, and nature of substances and they determine the concentration of chemical pollutants in soil, water,and air. I would recommend taking inorganic, organic, analytical, and physical chemistry as well as computer science, physics, and environmental science

3 0

2 years ago

ubstance A undergoes a first order reaction A®B with a half-life, t½, of 20 min at 25 °C. If the initial concentration of A in a

Stells [14]

Answer : The concentration of A after 80 min is, 0.100 M

Explanation :

Half-life = 20 min

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{20\text{ min}}$

$k=3.465\times 10^{-2}\text{ min}^{-1}$

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $3.465\times 10^{-2}\text{ min}^{-1}$

t = time passed by the sample = 80 min

a = initial amount of the reactant = 1.6 M

a - x = amount left after decay process = ?

Now put all the given values in above equation, we get

$80=\frac{2.303}{3.465\times 10^{-2}}\log\frac{1.6}{a-x}$

$a-x=0.100M$

Therefore, the concentration of A after 80 min is, 0.100 M

3 0

2 years ago

Need help this question QUICK

tino4ka555 [31]

The answer is number 2

4 0

3 years ago

A 34.57 mL sample of an unknown phosphoric acid solution is titrated with a 0.127 M sodium hydroxide solution. The equivalence p

Bas_tet [7]

<u>Answer:</u> The concentration of unknown phosphoric acid solution is 0.034 M

<u>Explanation:</u>

To calculate the concentration of acid, 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 $H_3PO_4$

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

We are given:

$n_1=3\\M_1=?M\\V_1=34.57mL\\n_2=1\\M_2=0.127M\\V_2=28.2mL$

Putting values in above equation, we get:

$3\times M_1\times 34.57=1\times 0.127\times 28.2\\\\M_1=\frac{1\times 0.127\times 28.2}{3\times 34.57}=0.034M$

Hence, the concentration of unknown phosphoric acid solution is 0.034 M

7 0

2 years ago

Why is the inner core's state of matter different from the outer core's state of matter

Ganezh [65]

Because the inner course is a totally different thing then the outer course

3 0

2 years ago