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3 years ago

Which describes the Sahara?

Chemistry

2 answers:

Lana71 [14]3 years ago

4 0

A desert that covers the northern third of Africa. hope i helped:]

finlep [7]3 years ago

3 0

The correct answer is - a desert that covers the northern third of Africa.

Sahara is the biggest desert in the world. It occupies the northern third of the African continent, thus being the absolutely most dominant landscape feature in North Africa. It stretches from the Atlantic coast on the west, to the Red Sea coastline on the east, and from the plateaus of Central Africa, to near the coastline of the Mediterranean sea. It is a desert that has been a natural barrier for the movement and dispersal of people, animals and plants since its formation, with its vastness, lack of water, lack of food, sand storms, extreme heat.

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A tank can hold up to 2500 liters of liquid. The tank initially contains 1000 liters of a brine solution with 50kg of salt. A br

Bogdan [553]

Answer:

67.93 kg.

Explanation:

See the attached pictures for detailed explanation.

8 0

3 years ago

(1) Write the net ionic equation for the reaction that occurs when equal volumes of 0.233 M aqueous acetylsalicylic acid (aspiri

AveGali [126]

Complete Question

The complete question is shown on the first uploaded image

Answer:

1) The ionic equation is

$HC_9H_7O_4 + (C_2 H_5)_3 N -----> C_9H_7O_4^- + (C_2 H_5)_3 NH^-$

At equilibrium The aniline will be favored

The pH of the solution is $pH = 7.12$

Explanation:

From the question we are told that

The concentration of aspirin is $C_A = 0.233M$

The acid dissociation constant for aspirin is $K_a = 3.0*10^{-4}$

The base dissociation constant for aniline is $K_b = 7.4 *10^{-10}$

The molecular formula for aspirin is $HC_9H_7O_4$

The molecular formula for aniline is $(C_2 H_5)_3 N$

So the net ionic reaction is

$HC_9H_7O_4 + (C_2 H_5)_3 N -----> C_9H_7O_4^- + (C_2 H_5)_3 NH^-$

Generally pKa is mathematically evaluated as

$pKa = -log(3.0*10^{-4})$

$= 3.52$

Generally pKb is mathematically represented as

$pKa = -log(7.4*10^{-10 })$

$= 9.13$

Generally

pKa + pKb = 14

So for the triethylammonium salt produced the pKa is

$pK_a__{s}} = 14 - 3.28$

$= 10.72$

As a result of the pKa of aspirin being lower that that of triethylammonium salt at equilibrium it implies that aniline would be favored

The pH of the solution is mathematically represented as

Since they are of equal mole

$pH = \frac{1}{2} (pKa + pKb + pKw)$

Where pKw is the pKw of water which has a value of 14

$pH = 0.5(14 + 3.52 + 3.28)$

$pH = 7.12$

5 0

3 years ago

Read 2 more answers

1. The volume of a gas is 10.0 liters and its temperature is 1500 K. If the temperature is

cupoosta [38]

Answer:

5 L

Explanation:

So this problem refers to Charles's law. You would use this formula..

$\frac{V_{I} }{T_{I} } = \frac{V_{F} }{T_{F} }$ (Initial volume / Initial Temperature) = (Final volume / Final Temperature)

For your problem, it would look like this...

$\frac{10L}{1500k} = \frac{V_{F} }{750k}$

You would cross multiply and your answer would be 5L.

To reassure yourself that the answer is correct, Charles law states that the Volume and the Temperature are directly proportional. Meaning if your temperature is decreasing, your volume <u>has</u> to decrease.

5 0

2 years ago

During photosynthesis, what gas do plants release

ELEN [110]

During photosynthesis, what gas do plants release - oxygen

5 0

2 years ago

Why might calcium also be called the calcium of citric acid

Stella [2.4K]

Calcium citrate malate contains the calcium salt of citric acid and malic acid

6 0

2 years ago