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2 years ago

Why is a control group important in an experiment?

Chemistry

1 answer:

bazaltina [42]2 years ago

8 0

A control group is an essential part of an
experiment because it allows you to eliminate and isolate these variables.

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Calculate the density of an object whose mass is 352 grams and has a volume of 469 mL please show work

mixer [17]

Answer:

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question we have

$density = \frac{352}{469} \\ = 0.750533..$

We have the final answer as

Hope this helps you

4 0

2 years ago

Charlie measures the mass of a metal three times and recorded 8.83 g,

Marina CMI [18]

Answer:what’s the answer

Explanation:

6 0

3 years ago

BH+ClO4- is a salt formed from the base B (Kb = 1.00e-4) and perchloric acid. It dissociates into BH+, a weak acid, and ClO4-, w

Len [333]

Answer:

The pH of 0.1 M BH⁺ClO₄⁻ solution is 5.44

Explanation:

Given: The base dissociation constant: $K_{b}$ = 1 × 10⁻⁴, Concentration of salt: BH⁺ClO₄⁻ = 0.1 M

Also, water dissociation constant: $K_{w}$ = 1 × 10⁻¹⁴

The acid dissociation constant ( $K_{a}$ ) for the weak acid (BH⁺) can be calculated by the equation:

$K_{a}. K_{b} = K_{w}$

$\Rightarrow K_{a} = \frac{K_{w}}{K_{b}}$

$\Rightarrow K_{a} = \frac{1\times 10^{-14}}{1\times 10^{-4}} = 1\times 10^{-10}$

Now, the acid dissociation reaction for the weak acid (BH⁺) and the initial concentration and concentration at equilibrium is given as:

Reaction involved: BH⁺ + H₂O ⇌ B + H₃O+

Initial: 0.1 M x x

Change: -x +x +x

Equilibrium: 0.1 - x x x

The acid dissociation constant: $K_{a} = \frac{\left [B \right ] \left [H_{3}O^{+}\right ]}{\left [BH^{+} \right ]} = \frac{(x)(x)}{(0.1 - x)} = \frac{x^{2}}{0.1 - x}$

$\Rightarrow K_{a} = \frac{x^{2}}{0.1 - x}$

$\Rightarrow 1\times 10^{-10} = \frac{x^{2}}{0.1 - x}$

$As, x$

$\Rightarrow 0.1 - x = 0.1$

$\therefore 1\times 10^{-10} = \frac{x^{2}}{0.1 }$

$\Rightarrow x^{2} = (1\times 10^{-10})\times 0.1 = 1\times 10^{-11}$

$\Rightarrow x = \sqrt{1\times 10^{-11}} = 3.16 \times 10^{-6}$

Therefore, the concentration of hydrogen ion: x = 3.6 × 10⁻⁶ M

Now, pH = - ㏒ [H⁺] = - ㏒ (3.6 × 10⁻⁶ M) = 5.44

Therefore, the pH of 0.1 M BH⁺ClO₄⁻ solution is 5.44

5 0

2 years ago

Calculate the amount of carbon dioxid gas in 1.505x10^23 molecules of the gas.

Daniel [21]

Explanation:

We need to find the amount of carbon dioxide gas in $1.505\times 10^{23}$ molecules of the gas.

We know that, 1 mole weighs 44 gram of carbon dioxide which contains $6.022\times 10^{23}$ number of molecules. It means that, $6.022\times 10^{23}$ number of molecules present in 44 grams of carbon dioxide molecule. So, $1.505\times 10^{23}$ number of molecules present in :

$=\dfrac{1.0505\times 10^{23}}{6.022\times 10^{23}}\times 44\\\\=7.675\ \text{grams}$

Hence, 7.675 grams of carbon dioxide is present in $1.505\times 10^{23}$ molecules of the gas.

4 0

2 years ago

For each reaction, identify the element that gets reduced and the element that gets oxidized. 2 AgCl + Zn ⟶ 2 Ag + ZnCl 2 2AgCl+

Mnenie [13.5K]

Answer:

Explanation:

Oxidation:

Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.

Reduction:

Reduction involve the gain of electron and oxidation number is decreased.

Oxidizing agents:

Oxidizing agents oxidize the other elements and itself gets reduced.

Reducing agents:

Reducing agents reduced the other element are it self gets oxidized.

Consider the following reaction:

2AgCl + Zn → 2Ag + ZnCl₂

In this reaction oxidation state of Zn on left side is 0 while on right side +2 so it gets oxidized and oxidation state of Ag on left side is +1 and on right side 0 so it get reduced.

4NH₃ + 3O₂ → 2N₂ + 6H₂O

In this reaction oxidation state of nitrogen on left side is -3 while on right side 0 so it gets oxidized and oxidation state of oxygen on left side is 0 and on right side -2 so it get reduced.

Fe₂O₃ + 2Al → Al₂O₃ + 2Fe

In this reaction oxidation state of iron on left side is +3 while on right side 0 so it gets reduced and oxidation state of Al on left side is 0 and on right side +3 so it get oxidized.

4 0

3 years ago