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3 years ago

10

Which veriable should he change, measure and control (temp of water, volume of water and mass of sodium chloride that dissolve )

in a dissolving investigation

1 answer:

erma4kov [3.2K]3 years ago

7 0

I would say
change: Temp
Measure: Mass
Control: Volume

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By making your decision, did you support the opinions of the mayor and/or the dam safety official? why or why not?

Nady [450]

An earthquake is a catastrophic<span> event that results from a gradual accumulation of stresses at fault lines. Clearly </span>catastrophism<span> is at work.</span>

6 0

3 years ago

Copper sulfate can crystalize as an anhydrate (no water in the crystal) or as three different hydrates (varying amounts of water

Maurinko [17]

Answer:

Two factors that might have a affect of which copper sulphate mineral will occur at a given location is:

A. Copper sulphate high solubility in water

B. Also it binds nicely with the sediments or the crystal.

Explanation:

As it is mentioned here that copper sulphate can be crystallized as an anhydrate which means that their is no waterin those crystals or can be as of those three different hydrates whose crystal structure varies with the amount of water present in it.

The four forms are also given of the copper sulphate are:

Bonatite
Boothite
Chalcanthite
Chalcocyanite

So, the two factors that might give an affect which type of copper sulphate mineral willoccur at a given location is:

A. The copper sulphate high solubility in water.

B. It binds extremely nicely with the sediments or say to the crystal. It is also regulated by plants.

8 0

3 years ago

in a second experiment, the total pressure is observed to be 58 atm. what is the partial pressure of the water vapor produced?

dimulka [17.4K]

This is an incomplete question, here is a complete question.

Nitroglycerine (C₃H₅N₃O₉) explodes with tremendous force due to the numerous gaseous products. The equation for the explosion of Nitroglycerine is:

$4C_3H_5N_3O_9(l)\rightarrow 12CO_2(g)+O_2(g)+6N_2(g)+10H_2O(g)$

A scientist conducts an experiment to characterize a bomb containing nitroglycerine. She uses a steel, ridge container for the test.

Volume of rigid steel container: 1.00 L

Molar mass of Nitroglycerine: 227 g/mol

Temperature: 300 K

Amount of Nitroglycerine tested: 227 g

Value for ideal gas constant, R: 0.0821 L.atm/mol.K

In a second experiment, the total pressure is observed to be 58 atm. what is the partial pressure of the water vapor produced?

Answer : The partial pressure of the water vapor is, 20.01 atm

Explanation :

First we have to calculate the moles of $C_3H_5N_3O_9$

$\text{Moles of }C_3H_5N_3O_9=\frac{\text{Given mass }C_3H_5N_3O_9}{\text{Molar mass }C_3H_5N_3O_9}=\frac{227g}{227g/mol}=1mol$

Now we have to calculate the moles of $CO_2,O_2,N_2\text{ and }H_2O$

The balanced chemical reaction is:

$4C_3H_5N_3O_9(l)\rightarrow 12CO_2(g)+O_2(g)+6N_2(g)+10H_2O(g)$

From the balanced chemical reaction we conclude that,

As, 4 moles of $C_3H_5N_3O_9$ react to give 12 moles of $CO_2$

So, 1 moles of $C_3H_5N_3O_9$ react to give $\frac{12}{4}=3$ moles of $CO_2$

and,

As, 4 moles of $C_3H_5N_3O_9$ react to give 1 moles of $O_2$

So, 1 moles of $C_3H_5N_3O_9$ react to give $\frac{1}{4}=0.25$ moles of $O_2$

and,

As, 4 moles of $C_3H_5N_3O_9$ react to give 6 moles of $N_2$

So, 1 moles of $C_3H_5N_3O_9$ react to give $\frac{6}{4}=1.5$ moles of $N_2$

and,

As, 4 moles of $C_3H_5N_3O_9$ react to give 10 moles of $H_2O$

So, 1 moles of $C_3H_5N_3O_9$ react to give $\frac{10}{4}=2.5$ moles of $H_2O$

Now we have to calculate the mole fraction of water.

$\text{Mole fraction of }H_2O=\frac{\text{Moles of }H_2O}{\text{Moles of }H_2O+\text{Moles of }CO_2+\text{Moles of }O_2+\text{Moles of }N_2}$

$\text{Mole fraction of }H_2O=\frac{2.5}{2.5+3+0.25+1.5}=0.345$

Now we have to calculate the partial pressure of the water vapor.

According to the Raoult's law,

$p_{H_2O}=X_{H_2O}\times p_T$

where,

$p_{H_2O}$ = partial pressure of water vapor gas = ?

$p_T$ = total pressure of gas = 58 atm

$X_{H_2O}$ = mole fraction of water vapor gas = 0.345

Now put all the given values in the above formula, we get:

$p_{H_2O}=X_{H_2O}\times p_T$

$p_{H_2O}=0.345\times 58atm=20.01atm$

Therefore, the partial pressure of the water vapor is, 20.01 atm

3 0

3 years ago

In the decomposition potassium nitride, 10.65 g of nitrogen form. How much potassium nitride was present initially ?

leonid [27]

Answer:

Mass = 99.8 g

Explanation:

Given data:

Mass of potassium nitride = ?

Mass of nitrogen produced = 10.65 g

Solution:

Chemical equation:

2K₃N→ 6K + N₂

Moles of nitrogen:

Number of moles = mass/ molar mass

Number of moles = 10.65 g / 28 g/mol

Number of moles = 0.38 mol

Now we will compare the moles of nitrogen with potassium nitride.

N₂ ; K₃N

1 : 2

0.38 : 2×0.38 =0.76

Mass of potassium nitride:

Mass = molar mass × number of moles

Mass = 131.3 g/mol × 0.76 mol

Mass = 99.8 g

7 0

3 years ago

A. 1720 kJ<br> B. 125.6 kJ<br> C. 3440 kJ<br> D. 4730 kJ

Feliz [49]

Answer:

Q = 3440Kj

Explanation:

Given data:

Mass of gold = 2kg

Latent heat of vaporization = 1720 Kj/Kg

Energy required to vaporize 2kg gold = ?

Solution:

Equation

Q= mLvap

It is given that heat required to vaporize the one kilogram gold is 1720 Kj thus, for 2 kg

by putting values,

Q= 2kg × 1720 Kj/Kg

Q = 3440Kj

7 0

3 years ago