krypton is the answer blah blah blah is this enough letters
Explanation:
Before proceeding, let's understand what thermosphere and mesosphere are;
The mesosphere is the third layer of the atmosphere, directly above the stratosphere and directly below the thermosphere.
The thermosphere is the layer in the Earth's atmosphere directly above the mesosphere and below the exosphere.
The meteors make it through the exosphere and thermosphere without much trouble because those layers don't have much air. But when they hit the mesosphere, there are enough gases to cause friction and create heat.
Temperatures in the mesosphere decrease with altitude. Because there are few gas molecules in the mesosphere to absorb the Sun's radiation, the
heat source is the stratosphere below. The mesosphere is extremely cold.
Satellites and the International Space Station orbit the Earth within the thermosphere.
Mesosphere;
- is directly above the stratosphere
- acts as a barrier to meteoroids
- is very cold
Thermosphere;
- reaches out into space
- is where satellites travel
Answer:
pH = 12.43
Explanation:
<em>...is titrating 212.7 mL of a 0.6800 M solution of hydrazoic acid (HN3) with a 0.2900 M solution of KOH. The p Ka of hydrazoic acid is 4.72. Calculate the pH of the acid solution after the chemist has added 571.6 mL of the KOH solution to it</em>.
To solve this question we need to know that hidrazoic acid reacts with KOH as follows:
HN3 + KOH → KN3 + H2O
<em>Moles KOH:</em>
0.5716L * (0.2900mol /L) =0.1658 moles of KOH
<em>Moles HN3:</em>
0.2127L * (0.6800mol/L) = 0.1446 moles HN3
As the reaction is 1:1, the KOH is in excess. The moles in excess of KOH are:
0.1658 moles - 0.1446 moles =
0.0212 mol KOH
In 212.7mL + 571.6mL = 784.3mL = 0.7843L
The molarity of KOH = [OH-] is:
0.0212 mol KOH / 0.7843L = 0.027M = [OH-]
The pOH is defined as -log [OH-]
pOH = -log 0.027M
pOH = 1.57
pH = 14 - pOH
pH = 12.43
<u>Answer</u>
79 ml
<u>Explanation</u>
You have 237 237 ml of ammonia, whose strength is 100%.
If you want to make it 75%, then;
let 75% ⇒ 237 ml of ammonia and
25% ⇒ x ml of water.
∴ x = (25% ×237) / 75%
= 5,925/75
= 79 ml of water.
Controlled variables: do not change as they must be held constant
Independent variables: are controlled and manipulated
Dependent variables: effected by changes to the independent variable
