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3 years ago

Helpppppp i hate chemistry

Chemistry

1 answer:

BigorU [14]3 years ago

8 0

Answer:

The first option: Strontium Fluorate.

Explanation:

because Fluorine and oxygen combines to make fluorate, Strontium stays the same.

p.s: i need help in geo and there's an exam tomorrow.

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n the laboratory, a general chemistry student measured the pH of a 0.342 M aqueous solution of ethylamine, C2H5NH2 to be 12.067.

Tasya [4]

Answer:

The value of $K_b$ of the an ethylamine is $4.121\times 10^{-4}$ .

Explanation:

The pH of the solution = 12.067

The pOH of the solution = 14 - pH =14-12.607 =1.933

$pOH=-\log[OH^-]$

$1.933=-\log[OH^-]$

$[OH^-]=0.0117 M$

$C_2H_5NH_2+H_2O\rightleftharpoons C_2H_5NH_3^{+}+OH^-$

Initially

0.342 M 0 0

At equilibrium

(0.342-x) x x

The value of x = $[OH^-]=0.0117 M$

The expression of $K_b$ is given as:

$K_b=\frac{[C_2H_5NH_3^{+}][OH^-]}{[C_2H_5NH_2]}$

$K_b=\frac{x^2}{(0.342-x)}$

$K_b=\frac{(0.0117 )^2}{(0.342-0.0117)}=4.121\times 10^{-4}$

The value of $K_b$ of the an ethylamine is $4.121\times 10^{-4}$ .

7 0

3 years ago

A worker is told her chances of being killed by a particular process are 1 in every 300 years. Should the worker be satisfied or

Pavlova-9 [17]

Answer:

(a) Yes, he should be worried. The Fatal accident rate (FAR) is too high according to standars of the industry. This chemical plant has a FAR of 167, where in average chemical plants the FAR is about 4.

(b) FAR=167 and Death poer person per year = 0.0033 deaths/year.

Explanation:

Asumming 50 weeks of work, with 40 hours/week, we have 2000 work hours a year.

In 300 years we have 600,000 hours.

With these estimations, we have (1/600,000)=1.67*10^(-6) deaths/hour.

If we have 2000 work hours a year, it is expected 0.0033 deaths/year.

$1.67*10^{-6} \frac{deaths}{hour}*2000 \frac{hours}{year}=0.0033 deaths/year$

The Fatal accident rate (FAR) can be expressed as the expected number of fatalities in 100 millions hours (10^(8) hours).

In these case we have calculated 1.67*10^(-6) deaths/hour, so we can estimate FAR as:

$FAR=1.67*10^{-6} \frac{deaths}{hour}*10^{8} hours=1.67*10^{2} =167$

A FAR of 167 is very high compared to the typical chemical plants (FAR=4), so the worker has reasons to be worried.

If we assume FAR=4, as in an average chemical plant, we expect

$4\frac{deaths}{10^{8} hour} *2000\frac{hours}{year}=8*10^{-5} \frac{deaths}{year}$

This is equivalent to say

$\frac{1}{8*10^{-5} } \frac{years}{death}=1.25*10^{4} \frac{years}{death} =12500 \, \frac{years}{death}$

The expected number of fatalities on a average chemical plant are one in 12500 years.

4 0

3 years ago

Both protons and neutrons (and their anti-particles) froze out:

VladimirAG [237]

I think Both protons and neutrons (and their anti-particles) froze out at 1013 K, about 0.0001 seconds after the Big Bang. Protons and neutrons are sub atomic particles of an atom that are found in the nucleus of an atom. Proton is the positively charge particle while the neutron has no charge. The proton positive charge accounts for the positive nuclear charge.

6 0

3 years ago

3 points

VLD [36.1K]

Answer:

<h3>The answer is 8.29 %</h3>

Explanation:

The percentage error of a certain measurement can be found by using the formula

$P(\%) = \frac{error}{actual \: \: number} \times 100\% \\$

From the question

actual density = 19.30g/L

error = 20.9 - 19.3 = 1.6

We have

$p(\%) = \frac{1.6}{19.3} \times 100 \\ = 8.290155440...$

We have the final answer as

Hope this helps you

5 0

3 years ago

True or false: Observing a physical property of a substance will change the substances' identity. I NEED IT NOWWWWW

ale4655 [162]

False

only observing chemical property will change its identity

5 0

2 years ago