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3 years ago

????.? .?.? . I have some question on Alef website

Chemistry

2 answers:

Andrew [12]3 years ago

8 0

B. crust, middle, core

Ganezh [65]3 years ago

3 0

The correct answer is B

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As the ph approaches 0, what happens to the concentration of h3o+ ions?

natta225 [31]

We know that

pH = -log[H+]

the pH value falls in between 0- 7 for acids

As the pH value increases the concentration of [H+] increases.

similarly as the value of pH approaches 0, the concentration of H+ increases

The solution said to become more acidic

Also

[H+] X [OH-] = 10^-14

Thus pH + pOH = 14

hence the concentration of OH- decreases as the pH approaches zero

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3 years ago

A tank contains 90 kg of salt and 2000 L of water. Pure water enters a tank at the rate 6 L/min. The solution is mixed and drain

sashaice [31]

Answer:

a) 90 kg

b) 68.4 kg

c) 0 kg/L

Explanation:

Mass balance:

$-w=\frac{dm}{dt}$

w is the mass flow

m is the mass of salt

$-v*C=\frac{dm}{dt}$

v is the volume flow

C is the concentration

$C=\frac{m}{V+(6-3)*L/min*t}$

$-v*\frac{m}{V+(6-3)*L/min*t}=\frac{dm}{dt}$

$-3*L/min*\frac{m}{2000L+(3)*L/min*t}=\frac{dm}{dt}$

$-3*L/min*\frac{dt}{2000L+(3)*L/min*t}=\frac{dm}{m}$

$-3*L/min*\int_{0}^{t}\frac{dt}{2000L+(3)*L/min*t}=\int_{90kg}^{m}\frac{dm}{m}$

$-[ln(2000L+3*L/min*t)-ln(2000L)]=ln(m)-ln(90kg)$

$-ln[(2000L+3*L/min*t)/2000L]=ln(m/90kg)$

$m=90kg*[2000L/(2000L+3*L/min*t)]$

a) Initially: t=0

$m=90kg*[2000L/(2000L+3*L/min*0)]=90kg$

b) t=210 min (3.5 hr)

$m=90kg*[2000L/(2000L+3*L/min*210min)]=68.4kg$

c) If time trends to infinity the division trends to 0 and, therefore, m trends to 0. So, the concentration at infinit time is 0 kg/L.

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3 years ago

It is easier to push a sofa across a rough surface like carpet than a smooth surface like a hardwood floor.

Gelneren [198K]

False, pushing a sofa on a hardwood floor would be easier than on carpet.

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3 years ago

What is the mass, in grams, of a sample of 6.12 × 10^24 atoms of manganese (Mn)? Show your work or explain the steps that you us

e-lub [12.9K]

6.12(1024)=(6.12)(1e+24)=6.12e+24 =

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3 years ago

Matt is conducting an experiment where he compares the properties of water and

NikAS [45]

Answer:

sitric acid from lemon

Explanation:

there

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3 years ago