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3 years ago

Which energy profile best shows that the enthalpy of formation of cs2 is 89.4 kj/mol?

1 answer:

5 0

Answer is: B. C(s) + 2S(s) + 89.4 kJ → CS2(l).

Missing question:
A. C(s) + 2S(s) → CS2(l) + 89.4 kJ.
B. C(s) + 2S(s) + 89.4 kJ → CS2(l).
C. C(s) + 2S(s) + 89.4 kJ → CS2(l) + 89.4 kJ.
D. C(s) + 2S(s) → CS2(l).
Because enthalpy of the system is greater that zero, this is endothermic reaction (<span>chemical reaction that absorbs more energy than it releases)</span>, heat is included as a reactant.

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Which beakers in the model contain solid insoluble substances?

ladessa [460]

Although the models are not provided, I was able to find them and the beakers with solid present in them are:
1C
2A
2C
3A
3C

This is determined by the fact that the beakers all have a piece of closely packed substance laying at the bottom. This closely packed lattice is characteristic of solid substances, and the fact that they exist in the solution in the solid states indicates that they are insoluble.

7 0

3 years ago

According to de Broglie, which of these objects does not have a wavelength?

polet [3.4K]

Answer: Option D is correct.

Explanation: Equation given by de Broglie is:

$\lambda =\frac{h}{mv}$

where, $\lambda$ = wavelength of the particle

h = Planck's constant

m = mass of the particle

v = velocity of the particle

In option A, football will have some mass and is moving with a velocity of 25 m/s, hence it will have some wavelength.

In Option B, unladen swallow also have some mass and is moving with a velocity of 38 km/hr, hence it will also have some wavelength.

In Option C, a person has some mass and is running with a velocity of 7 m/hr, hence it will also have some wavelength.

As, the momentum of these particles are large, therefore the wavelength will be of small magnitude and hence, is not observable.

From the above, it is clearly visible that all the options are having some wavelength, so option D is correct.

7 0

3 years ago

If someone consumes 22 g of sodium chloride per day, what mass (in grams) of sodium does that person consume? Sodium chloride is

kompoz [17]

Answer:

Mass of sodium, the person daily consume = 8.58 g

Explanation:

Given that:-

sodium chloride is 39% sodium by mass which means that:-

100 g of sodium chloride contains 39 g of sodium

Also,

1 g of sodium chloride contains 0.39 g of sodium

So, Given mass = 22 g

22 g of sodium chloride contains $0.39\times 22$ g of sodium

<u>Mass of sodium, the person daily consume = 8.58 g</u>

4 0

3 years ago

This stadium can hold 100,000, or 1 x 10^5, people. The number of atoms in a grain of iron is about 1 x 10^18. Would you need 1

polet [3.4K]

<h3>Answer:</h3>

1 x 10^13 stadiums

<h3>Explanation:</h3>

From the question;

1 x 10^5 people can fill 1 stadium

We are given, 1 x 10^18 atoms of iron

We are required to determine the number of stadiums that 1 x 10^18 atoms of iron would occupy.

We are going to assume that a stadium would occupy a number of atoms equivalent to the number of people.

Therefore;

One stadium = 1 x 10^5 atoms

Then, to find the number of stadiums that will be occupied by 1 x 10^18 atoms;

No. of stadiums = Total number of atoms ÷ Atoms in a single stadium

= 1 x 10^18 atoms ÷ 1 x 10^5 atoms

= 1 x 10^13 stadiums

Therefore, 1 x 10^18 atoms of iron would occupy 1 x 10^13 stadiums

7 0

3 years ago

Calculate the volume of 1M NaOH required to neutralize 200 cc of 2M HCI. What mass of sodium

Nezavi [6.7K]

NaOH+HCl-> NaCl+H2O

1 mole of NaOH

1 mole of HCl.

To calculate volume of NaOH

CaVa/CbVb= Na/Nb

Where Ca=2M

Cb=1M

Va=200cm³

Vb=xcm³

Substitute into the equation.

2×200/1×Vb=1/1

400/Vb=1/1

Cross multiply

Vb×1=400×1

Vb=400cm³

To calculate the mass of sodium chloride, NaCl from the neutralization rxn.

Mole of NaCl=1

Molar mass of NaCl= 23+35.5=58.5

Mass=xgrammes.

Mass of NaCl=Number of moles × Molar mass.

Substitute

Mass of NaCl= 1×58.5

=58.5g

This is what I could come up with.

5 0

3 years ago