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svlad2 [7]
3 years ago
13

Darkness conceals hazards such as

Chemistry
1 answer:
Studentka2010 [4]3 years ago
7 0
Same I agree with this mans statement good job bro bro I'm just trynna finish this thing so I got 100 on this app
You might be interested in
. A sample of crude oil has a density of 0.87 g/mL. What volume (in liters) does a 3.6 kg sample of this oil occupy
gayaneshka [121]

Answer:

The volume is 4.13793 L

Explanation:

Density is a quantity that expresses the relationship between the mass and the volume of a body, so it is defined as the quotient between the mass and the volume of a body:

density=\frac{mass}{volume}

Density is a characteristic property of every body or substance.

The most commonly used units of density are \frac{kg}{m^{3} } or \frac{g}{cm^{3} } for solids, and \frac{kg}{L} or \frac{g}{mL} for liquids and gases.

In this case, you know:

  • density= 0.87 \frac{g}{mL}
  • mass= 3.6 kg= 3,600 g (being 1 kg=1,000 g)
  • volume= ?

Replacing:

0.87\frac{g}{mL} =\frac{3,600 g}{volume}

Solving:

volume =\frac{3,600 g}{0.87\frac{g}{mL}}

volume= 4,137.93 mL

Being 1,000 mL=1 L, then volume= 4,137.93 mL= 4.13793 L

<u><em>The volume is 4.13793 L</em></u>

5 0
3 years ago
Potassium nitrate has a lattice energy of -163.8 kcal/mol and a heat of hydration of -155.5 kcal/mol.
Brut [27]

Answer:

<em>293.99 g </em>

OR

<em>0.293 Kg</em>

Explanation:

Given data:

Lattice energy of Potassium nitrate (KNO3) = -163.8 kcal/mol

Heat of hydration of KNO3 = -155.5 kcal/mol

Heat to absorb by KNO3 = 101kJ

To find:

Mass of KNO3 to dissolve in water = ?

Solution:

Heat of solution = Hydration energy - Lattice energy

                           = -155.5 -(-163.8)

                           = 8.3 kcal/mol

We already know,

1 kcal/mol = 4.184 kJ/mole

Therefore,

= 4.184 kJ/mol x 8.3 kcal/mol

= 34.73 kJ/mol

Now, 34.73 kJ of heat is absorbed when 1 mole of KNO3 is dissolved in water.

For 101 kJ of heat would be

= 101/34.73

= 2.908 moles of KNO3

Molar mass of KNO3 = 101.1 g/mole

Mass of KNO3 = Molar mass x moles

                         = 101.1 g/mole  x  2.908

                         = 293.99 g

                         = 0.293 kg

<em><u>293.99 g potassium nitrate has to dissolve in water to absorb 101 kJ of heat. </u></em>     

4 0
3 years ago
Noah and Nina are 15 m apart in a closed room. Noah says the same sentence twice. The first time, Nina does not hear the sound,
In-s [12.5K]

The air molecules in the compressions of the second wave are denser, so the sound is louder.

<h3>What is a sound wave?</h3>

Sound waves are longitudinal waves that travel through a medium like air or water.

In a closed room, Noah and Nina are sitting 15 m apart.

As Noah says the same sentence twice, Nina does not hear the sound the first time but she does hear the sentence the second time.

This happens as the air molecules in the compressions of the second wave are denser. As a result, the sound is louder.

The correct option is ''The air molecules in the compressions of the second wave are denser, so the sound is louder''.

Learn more about the sound wave here:

brainly.com/question/1554319

#SPJ1

5 0
1 year ago
Which of these elements has an atom with the most stable outer electron configuration? * Cl Ca Ne Na
SashulF [63]

Answer:

Neon (Ne) has the most stable outer electron configuration because the outer electron is completely filled and it has octet structure

Explanation:

The configuration of these elements is as follows;

Cl₁₇ = 2, 8,7 (the outer electron is 7)

Ca₂₀ = 2,8,8,2 (the outer electron is 2)

Ne₁₀ = 2,8 (the outer electron is 8)

Na₁₁ = 2,8,1 (the outer electron is 1)

Based on the outer electron value above, Neon (Ne) has the most stable outer electron configuration because the outer electron is completely filled and it has octet structure.

6 0
3 years ago
A 0.15 m solution of chloroacetic acid has a ph of 1.86. What is the value of ka for this acid?
dem82 [27]

Answer: 1.67\times 10^{-3}

Explanation:

ClCH_2COOH\rightarrow ClCH_2COO^-+H^+

   cM              0             0

c-c\alpha        c\alpha          c\alpha  

So dissociation constant will be:

K_a=\frac{(c\alpha)^{2}}{c-c\alpha}

Given:  c = 0.15 M

pH = 1.86

K_a = ?

Putting in the values we get:

Also pH=-log[H^+]

1.86=-log[H^+]

[H^+]=0.01

[H^+]=c\times \alpha

0.01=0.15\times \alpha

\alpha=0.06

As [H^+]=[ClCH_2COO^-]=0.01

K_a=\frac{(0.01)^2}{(0.15-0.15\times 0.06)}

K_a=1.67\times 10^{-3]

Thus the vale of K_a for the acid is 1.67\times 10^{-3}

4 0
3 years ago
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