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3 years ago

Energy 1:Question 3

1 answer:

3 0

Answer: The statement, atoms in the sand were moving more quickly best describes why the temperature of the sand increased.

Explanation:

As Sun rises in the morning everyday and the heat energy radiations given by the Sun falls on a number of objects on our surroundings. As a result, the objects absorb this heat energy till afternoon due to which they become hot.

Hence, atoms of the objects gain kinetic energy due to which they move quickly. This shows that the temperature of the object (sand here) increases.

When Maria walked in the same area in the afternoon, the sand was hot as its particles have gained kinetic energy due to which they move rapidly from one place to another. Hence, sand feels more hot in the afternoon in the same area where she walked.

Thus, we can conclude that the statement the atoms in the sand were moving more quickly best describes why the temperature of the sand increased.

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Minerals are very useful to us. Which of the following is a false statement? Question options: Pyrite is an ore of gold and is u

lilavasa [31]

Answer:

The false statement is :

Pyrite is an ore of gold and is used in jewelry making.
Cobalt is not used in medicine.

Explanation:

Pyrite is an ore of iron sulfide found on the Earth and in coal, limestone and in many deposits of metallic ores. Due to its luster and pale yellowish color it appears as gold due to which it is also termed as Fool's gold.

It is used in firearms , in production of sulfur dioxide gas, etc.

Cobalt is used as medicine to treat cancer patient. Co-60 is used in treatment of cancer in which gamma rays produced by Co-60 are used to kill tumor cells in a cancer patient.

Where as talc is used in industries like : paper making, food, paints, plastics etc. Quartz is primary material used to prepare glass and cobalt is used as

4 0

3 years ago

Describe Write your own caption for this photo.

koban [17]

Answer:

Sit by the fire to warm up

Explanation:

5 0

2 years ago

A 1.00 g sample of a metal X (that is known to form X ions in solution) was added to 127.9 mL of 0.5000 M sulfuric acid. After a

Semenov [28]

Answer: The metal having molar mass equal to 26.95 g/mol is Aluminium

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$ .....(1)

Molarity of NaOH solution = 0.5000 M

Volume of solution = 0.03340 L

Putting values in equation 1, we get:

$0.5000M=\frac{\text{Moles of NaOH}}{0.03340L}\\\\\text{Moles of NaOH}=(0.5000mol/L\times 0.03340L)=0.01670mol$

The chemical equation for the reaction of NaOH and sulfuric acid follows:

$2NaOH+H_2SO_4\rightarrow Na_2SO_4+H_2O$

By Stoichiometry of the reaction:

2 moles of NaOH reacts with 1 mole of sulfuric acid

So, 0.01670 moles of NaOH will react with = $\frac{1}{2}\times 0.01670=0.00835mol$ of sulfuric acid

Excess moles of sulfuric acid = 0.00835 moles

Calculating the moles of sulfuric acid by using equation 1, we get:

Molarity of sulfuric acid solution = 0.5000 M

Volume of solution = 127.9 mL = 0.1279 L (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

$0.5000M=\frac{\text{Moles of }H_2SO_4}{0.1279L}\\\\\text{Moles of }H_2SO_4=(0.5000mol/L\times 0.1279L)=0.06395mol$

Number of moles of sulfuric acid reacted = 0.06395 - 0.00835 = 0.0556 moles

The chemical equation for the reaction of metal (forming $M^{3+}$ ion) and sulfuric acid follows:

$2X+3H_2SO_4\rightarrow X_2(SO_4)_3+3H_2$

By Stoichiometry of the reaction:

3 moles of sulfuric acid reacts with 2 moles of metal

So, 0.0556 moles of sulfuric acid will react with = $\frac{2}{3}\times 0.0556=0.0371mol$ of metal

To calculate the molar mass of metal for given number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Mass of metal = 1.00 g

Moles of metal = 0.0371 moles

Putting values in above equation, we get:

$0.0371mol=\frac{1.00g}{\text{Molar mass of metal}}\\\\\text{Molar mass of metal}=\frac{1.00g}{0.0371mol}=26.95g/mol$

Hence, the metal having molar mass equal to 26.95 g/mol is Aluminium

6 0

3 years ago

In chemistry what contains the smallest amount of matter

Agata [3.3K]

C. 2,500Dg Im pretty sure thats it

3 0

4 years ago

Consider the reaction: <img src="https://tex.z-dn.net/?f=NiO%28s%29%2BCO%28g%29%20%5Crightleftharpoons%20Ni%28s%29%2BCO_2%28g%29

sasho [114]

Answer:

Molar concentration of CO₂ in equilibrium is 0.17996M

Explanation:

Based on the reaction:

NiO(s) + CO(g) ⇆ Ni(s) + CO₂(g)

kc is defined as:

kc = [CO₂] / [CO] = 4.0x10³ (1)

As initial concentration of CO is 0.18M, the concentrations in equilibrium are:

[CO] = 0.18000M - x

[CO₂] = x

Replacing in (1):

4.0x10³ = x / (0.18000-x)

720 - 4000x = x

720 = 4001x

x = 0.17996

Thus, concentrations in equilibrium are:

[CO] = 0.18000M - 0.17996 = 4.0x10⁻⁵

[CO₂] = x = 0.17996M

Thus, molar concentration of CO₂ in equilibrium is 0.17996M

I hope it helps!

5 0

3 years ago