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3 years ago

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Chemistry

1 answer:

photoshop1234 [79]3 years ago

4 0

Answer:

Atomic radius is directly proportional to Metallic reactivity in group 2.

Explanation:

Atomic radius is directly proportional to Metallic reactivity in group 2.

As we move down the group in group 2 which is called as the alkaline earth metals, the atomic number increases due to which the subshell increases. And the outermost shell's electron are less tightly held to the nucleus of the atom. Since the electrons are loosely held that means they can easily participate in reactions and that what makes it reactive down the 2nd group. Therefore alkaline earth metals with higher atomic number are more chemically reactive.

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The empirical formula of styrene is CH; its molar mass is 104.1 g/mol. What is the molecular formula of styrene

frez [133]

The atomic mass of carbon is 12.011 g/mol.
The atomic mass of hydrogen is 1.00794 g/mol.

This means the molar mass of CH is

$12.011+1.00794=13.01894 \text{ g/mol}$

Dividing the given molar mass by this, $\frac{104.1}{13.01894} \approx 8$

This means the molecular formula is $\boxed{\text{C}_{8}\text{H}_{8}}$

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2 years ago

You need to prepare .200M solution of hydrochloric acid (HCl). If you took out .830ml of the 12.0M stock solution. How much wate

Alenkinab [10]

Answer:

You must add 48.97 mL of water to make the 0.200 M diluted solution.

Explanation:

In chemistry, dilution is the reduction in concentration of a chemical in a solution. In other words, it is the process of reducing the concentration of solute in solution, simply adding more solvent to the solution.

In a dilution, the quantity or mass of the solute is not changed but only that of the solvent. As only solvent is being added, by not increasing the amount of solute the concentration of the solute decreases.

The expression for the dilution calculations is:

Cinitial* Vinitial = Cfinal* Vfinal

In this case:

Cinitial= 12 M
Vinitial= 0.830 mL
Cfinal= 0.200 M
Vfinal= ?

Replacing:

12 M*0.830 mL= 0.200 M*Vfinal

Solving:

$Vfinal=\frac{12 M*0.830 mL}{0.200 M}$

Vfinal= 49.8 mL

Since 0.830 mL is the volume you initially have of HCl, the amount of water you must add is:

49.8 mL - 0.830 mL= 48.97 mL

<u><em>You must add 48.97 mL of water to make the 0.200 M diluted solution.</em></u>

7 0

3 years ago

0.50 g of hydrogen chloride (HCl) is dissolved in water to make 4.0 L of solution. What is the pH of the resulting hydrochloric

svlad2 [7]

Explanation:

Given the mass of HCl is ---- 0.50 g

The volume of solution is --- 4.0 L

To determine the pH of the resulting solution, follow the below-shown procedure:

1. Calculate the number of moles of HCl given by using the formula:

$number of moles of a substance=\frac{given mass of the substance}{its molecular mass}$

2. Calculate the molarity of HCl.

3. Calculate pH of the solution using the formula:

$pH=-log[H^+]$

Since HCl is a strong acid, it undergoes complete ionization when dissolved in water.

$HCl(aq)->H^+(aq)+Cl^-(aq)$

Thus, $[HCl]=[H^+]$

Calculation:

1. Number of moles of HCl given:

$number of moles of a substance=\frac{given mass of the substance}{its molecular mass}\\=0.50g/36.5g/mol\\=0.0137mol$

2. Concentration of HCl:

$Molarity of HCl=\frac{number of moles of HCl}{its molar mass}\\=\frac{0.0137 mol}{4.0 L} \\= 0.003425 M$

3. pH of the solution:

$pH=-log[H^+]\\=-log(0.003425)\\=2.47$

Hence, pH of the given solution is 2.47.

3 0

3 years ago

A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next fe

Fantom [35]

Answer:

Explanation:

The molecules in both metal and surrounding air will start moving slower because of the sudden decrease in environment tmeperature. The thermal energy around the metal plate decreases, also decreasing the kinetic energy.

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3 years ago

If an old car burns 0.05 mL oil every mile, How much oil will it burn if driven 100,000 miles? Show your answer in mL and L?.

Irina18 [472]

0.05 * 100000

= 5000ml

= 5L

7 0

3 years ago