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3 years ago

Help help help. please help me

Chemistry

1 answer:

inysia [295]3 years ago

4 0

Answer:

Explanation:

Solar panels are not toxic, so option A goes out the window.

Aesthetics don't really matter, so option B follows it out.

Option C makes a little sense, but less so than Option D. They aren't nearly as heavy as some of our current energy production methods.

Solar panels are expensive, hard to store properly, and most are between 15 and 20 percent efficiency, compared with a diesel motor's 40 percent.

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A chemist used 6.5 moles of water in this reaction. How many grams of water were used?

denpristay [2]

Answer:

$\boxed {\boxed {\sf 120 \ or \ 117 \ grams \ H_2O \ depending \ on \ significant \ figures }}$

Explanation:

We want to convert from moles of water to grams of water.

First, find the molar mass of water (H₂O) Look on the Periodic Table for the masses of hydrogen and oxygen.

Hydrogen (H): 1.008 g/mol
Oxygen (O): 15.999 g/mol

Next, add up the number of each element in water. The subscript of 2 comes after the H, so there are 2 moles of hydrogen.

2 Hydrogen: (1.008 g/mol*2) = 2.016 g/mol

Finally, add the molar mass of 2 hydrogen and 1 oxygen.

2.016 g/mol (2 Hydrogen) + 15.999 g/mol (1 oxygen)= 18.015 g/mol

Next, find the grams in 6.5 moles.

Use the molar mass we just found as a ratio.

$molar \ mass \ ratio: \frac{18.015 \ g \ H_2O}{1 \ mol \ H_2O}$

We want to find the grams in 6.5 moles. We can multiply the ratio above by 6.5

$6.5 \ mol \ H_2O * \frac{18.015 \ g \ H_2O}{1 \ mol \ H_2O}$

Multiply. Note that the moles of H₂O will cancel each other out.

$6.5 * \frac{18.015 \ g \ H_2O}{1}$

$6.5 * {18.015 \ g \ H_2O}$

$117.0975 \ g \ H_2O$

If we want to round to the technically correct significant figures, it would be 2 sig figs. The original measurement, 6.5, has 2 (6 and 5).

$\approx 120 \ g \ H_2O$

6 0

3 years ago

What masses of sodium chloride, magnesium chloride, sodium sulfate, calcium chloride, potassium chloride, and sodium bicarbonate

andreyandreev [35.5K]

Answer:

NaCl: 184g

MgCl₂: 6.60g

Na₂SO₄: 9.26g

CaCl₂: 1.28g

KCl: 0.70g

NaHCO₃: 0.13g

Explanation:

To convert these concentrations to masses we need to convert molarity to moles and moles to grams using molar mass of each salt:

[CaCl₂] = [Ca²⁺] = 0.0115M

[HCO₃⁻] = [NaHCO₃] = 0.0015M

[SO₄²⁻] = [Na₂SO₄] = 0.0652M

[Mg²⁺] = [MgCl₂] = 0.0693M

[K⁺] = [KCl] = 0.0094M

And using the concentration of Cl⁻:

[Cl⁻] = [NaCl] + 2[MgCl₂] + 2[CaCl₂] + [KCl]

[3.32] = [NaCl] + 2[0.0693] + 2[0.0115] + [0.0094]

[NaCl] = 3.149M

The masses you need are:

<em>NaCl (Molar mass: 58.44g/mol):</em>

3.149mol/L * 1L * (58.44g/mol) =

<em>MgCl₂ (Molar mass: 95.211g/mol):</em>

0.0693mol/L * 1L * (95.211g/mol) =

Na₂SO₄<em> (Molar mass: 142.04g/mol):</em>

0.0652mol/L * 1L * (142.04g/mol) =

CaCl₂<em> (Molar mass: 110.98g/mol):</em>

0.0115mol/L * 1L * (110.98g/mol) =

KCl<em> (Molar mass: 74.55g/mol):</em>

0.0094mol/L * 1L * (74.55g/mol) =

<em>NaHCO₃ (Molar mass: 84g/mol):</em>

0.0015mol/L * 1L * (84g/mol) =

<h3>0.13g NaHCO₃</h3>

7 0

3 years ago

Which neutral atom is isoelectronic with p-3

worty [1.4K]

Answer:

srry...

Explanation:

5 0

3 years ago

How many atoms of oxygen are in 4.00 moles of N2O5

SVETLANKA909090 [29]

Answer:

there are 20 oxygen atoms in 4.00 moles of Dinitrogen pentoxide

Explanation:

there are 2 atoms in an oxygen molecule , so each oxygen molecules has at least 2. Dinitrogen pentoxide is N2O5, which has 7 atoms, 2 nitrogen and 5 oxygen. 1 molecule of N2O5 has 5 oxygen atoms, so 4 of then would be 20

8 0

3 years ago

which of the following activities could cause liquid molecules to overcome intermolecular attractive forces and become gas molec

Anna [14]

The answer is C. increasing the temperature of the liquid.

Increasing the temperature of the liquid also means that you are providing energy to the liquid, which makes the molecules overcome intermolecular attractive forces, move more constantly, and become gas molecules.

Hope this would help~

3 0

3 years ago