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3 years ago

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About 3% of the water on Earth is freshwater. Only about 40% of that freshwater is available for human use. Why is so much fresh

water unavailable for human use?

2 answers:

suter [353]3 years ago

6 0

About 60% of Earth's freshwater is frozen in the Arctic and Antarctic.

xenn [34]3 years ago

4 0

Because most of the fresh water is made up of glaciers and ice

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Help me! Who ever gets to answer and has the best answer gets brainliest (very easy!)

Katen [24]

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3 years ago

Read 2 more answers

What is a mole?

leva [86]

It's hard to relate a mole to carbon or sulfur. Imagine if I walked up to you and said, "What's the relation between a dozen and donuts?"

A mole is a form of measurement for atoms, more specifically, 6.02 * 10^23 atoms. I suppose you could relate it to Carbon or Sulfur, since the number of atoms of each are usually measured in moles.

Carbon and Sulfur don't have a set number of moles (Just like donuts don't have to be a dozen), so it's hard to answer your second question.
In the atomic table, the number you see under the element is the molar mass, which is the weight of an a mole of the element. In this way, I guess there's a mole of Carbon and Sulfur present, if we're looking at the periodic table.

-T.B.

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3 years ago

150 mL of 0.25 mol/L magnesium chloride solution and 150 mL of 0.35 mol/L silver nitrate solution are mixed together. After reac

Murljashka [212]

Answer:

$0.175\; \rm mol \cdot L^{-1}$ .

Explanation:

Magnesium chloride and silver nitrate reacts at a $2:1$ ratio:

$\rm MgCl_2\, (aq) + 2\, AgNO_3\, (aq) \to Mg(NO_3)_2 \, (aq) + 2\, AgCl\, (s)$ .

In reality, the nitrate ion from silver nitrate did not take part in this reaction at all. Consider the ionic equation for this very reaction:

$\begin{aligned}& \rm Mg^{2+} + 2\, Cl^{-} + 2\, Ag^{+} + 2\, {NO_3}^{-} \\&\to \rm Mg^{2+} + 2\, {NO_3}^{-} + 2\, AgCl\, (s)\end{aligned}$ .

The precipitate silver chloride $\rm AgCl$ is insoluble in water and barely ionizes. Hence, $\rm AgCl\!$ isn't rewritten as ions.

Net ionic equation:

$\begin{aligned}& \rm Ag^{+} + Cl^{-} \to AgCl\, (s)\end{aligned}$ .

Calculate the initial quantity of nitrate ions in the mixture.

$\begin{aligned}n(\text{initial}) &= c(\text{initial}) \cdot V(\text{initial}) \\ &= 0.25\; \rm mol \cdot L^{-1} \times 0.150\; \rm L \\ &= 0.0375\; \rm mol \end{aligned}$ .

Since nitrate ions $\rm {NO_3}^{-}$ do not take part in any reaction in this mixture, the quantity of this ion would stay the same.

$n(\text{final}) = n(\text{initial}) = 0.0375\; \rm mol$ .

However, the volume of the new solution is twice that of the original nitrate solution. Hence, the concentration of nitrate ions in the new solution would be $(1/2)$ of the concentration in the original solution.

$\begin{aligned} c(\text{final}) &= \frac{n(\text{final})}{V(\text{final})} \\ &= \frac{0.0375\; \rm mol}{0.300\; \rm L} = 0.175\; \rm mol \cdot L^{-1}\end{aligned}$ .

6 0

3 years ago

Which of these elements exhibits chemical behavior similar to that of oxygen? select one:

scoray [572]

Answer:
Sulfur (Option-C) <span>exhibits chemical behavior similar to that of oxygen.

Explanation:
Sulfur has same chemical properties as that of Oxygen because both of them belongs to same group in the periodic table. Also, the similarity of chemical behaviour among the group members is due to same number of electrons in their valence shells.
For examole, the electronic configuration of Oxygen is,

1s</span>², 2s², 2p⁴

There are six valence electrons in the valence shell (i.e. 2) of Oxygen.

Now for Sulfur,
1s², 2s², 2p⁶, 3s², 3p⁴

There are six valence electrons in the valence shell (i.e. 3) of Sulfur.

Therefore, both elements tends to gain 2 electrons in a reaction and form O⁻² and S⁻² respectively.

3 0

3 years ago

Chemical reactions forming ions _____.

Sergeu [11.5K]

The answer should be <span>balance electrically

</span><span>Chemical reactions that form ions should have a balanced charge. The example of the reaction is HCl. When forming ions, the equation should be:
HCl => </span> $H^{+}$ + $Cl^{-}$
In this case, the hydrogen has one plus charge and chlorine has one negative charge. The resultant should be zero, so it's balanced.

4 0

3 years ago