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2 years ago

Calculate the pH of a solution that has a [OH−] of 2.6 × 10^−6 M.

Chemistry

1 answer:

TiliK225 [7]2 years ago

7 0

Answer:

A. 8.4

Explanation:

[OH⁻] = 2.6 × 10⁻⁶ Take the negative log of each side

-log[OH⁻] = pOH = 5.59 Apply the pH/pOH relation

pH + pOH = 14.00 Insert the value of pOH

pH + 5.59 = 14.00 Subtract 5.59 from each side

pH = 14.00 -5.59 = 8.41

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melomori [17]

Cells and microorganisms are extremely complex

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2 years ago

Read 2 more answers

1. A cupcake show makes and delivers specialized cupcakes. It will cost someone $30 for

lorasvet [3.4K]

Answer:

2.5

Explanation:

The given costs for the purchase and delivery of the cupcakes are;

The cost of 10 cupcakes and the delivery fee = $30

The cost of 25 cupcakes and the delivery fee = $67.50

Let 'c' represent the fixed cost of delivery of the cup cakes, and let 'x' represent the cost of each cup cake, we have;

30 = 10·x + c...(1)

67.50 = 25·x + c...(2)

Subtracting equation (1) from equation (2) gives;

67.50 - 30 = 37.50 = 25·x - 10·x + c - c = 15·x

∴ x = 37.50/15 = 2.5

The cost of each cupcake, x = 2.5

(∴ The delivery fee = 30 - 10 × 2.5 = 5)

The cost of each cupcake is 2.5.

8 0

2 years ago

Lead(II) nitrate and ammonium iodide react to form lead(II) iodide and ammonium nitrate according to the reaction Pb ( NO 3 ) 2

nikklg [1K]

Answer : The volume of $NH_4I$ solution required is, 2.93 L

The number of moles of $PbI_2$ formed from the reaction is, 0.662 moles.

Explanation :

First we have to calculate the initial moles of $Pb(NO_3)_2$ .

$\text{Moles of }Pb(NO_3)_2=\text{Concentration of }Pb(NO_3)_2\times \text{Volume of solution}$

$\text{Moles of }Pb(NO_3)_2=0.700M\times 0.945L=0.662mol$

Now we have to calculate the moles of $NH_4I$

The balanced chemical reaction is:

$Pb(NO_3)_2(aq)+2NH_4I(aq)\rightarrow PbI_2(s)+2NH_4NO_3(aq)$

From the balanced chemical reaction we conclude that,

As, 1 mole of $Pb(NO_3)_2$ react with 2 moles of $NH_4I$

So, 0.662 mole of $Pb(NO_3)_2$ react with $0.662\times 2=1.32$ moles of $NH_4I$

Now we have to calculate the volume of $NH_4I$

$\text{Volume of }NH_4I=\frac{\text{Moles of }NH_4I}{\text{Concentration of }NH_4I}$

$\text{Volume of }NH_4I=\frac{1.32mol}{0.450mol/L}=2.93L$

Now we have to calculate the moles of $PbI_2$

From the balanced chemical reaction we conclude that,

As, 1 mole of $Pb(NO_3)_2$ react to give 1 moles of $PbI_2$

So, 0.662 mole of $Pb(NO_3)_2$ react to give 0.662 moles of $PbI_2$

Thus, the number of moles of $PbI_2$ formed from the reaction is, 0.662 moles.

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2 years ago

Which equation represents the correct net ionic equation for the reaction between Ca(OH)2 and H2SO4?

Georgia [21]

<u>Answer:</u> The correct net ionic equation for the reaction is $2H^{+}(aq)+2OH^{-}(aq)\rightarrow 2H_2O(l)$

<u>Explanation:</u>

Net ionic equation is defined as the equations in which spectator ions are not included.

Spectator ions are the ones that are present equally on the reactant and product sides. They do not participate in the reaction.

The balanced molecular equation is:

$Ca(OH)_2(aq)+H_2SO_4(aq)\rightarrow CaSO_4(aq)+2H_2O(l)$

The complete ionic equation follows:

$Ca^{2+}(aq)+2OH^-(aq)+2H^+(aq)+SO_4^{2-}(aq)\rightarrow 2Ca^{2+}(aq)+SO_4^{2-}(aq)+H_2O(l)$

As calcium and sulfate ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

$2H^{+}(aq)+2OH^{-}(aq)\rightarrow 2H_2O(l)$

Hence, the correct net ionic equation for the reaction is $2H^{+}(aq)+2OH^{-}(aq)\rightarrow 2H_2O(l)$

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2 years ago

Which statement best describes how photosynthesis follows the law of conservation of mass?

leva [86]

Answer:

O The number of oxygen atoms in the reactants used by this process equals the total number of oxygen atoms in the products.

Explanation:

The statement that best describes how photosynthesis follows the law of conservation of mass is that the number of oxygen atoms in the reactants used by this process is equal to the total number of oxygen atoms in the products.

The equation of photosynthesis reaction is given as:

6CO₂ + 6H₂O → C₆ H₁₂ O₆ + 6O₂

According to the law of conservation of mass, matter is neither created nor destroyed during the course of a chemical reaction.

By the virtue of this, the number of oxygen atom on both sides of the expression must be the same. Also, the number of carbon and hydrogen atoms must also be the same.

8 0

2 years ago