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2 years ago

What is the molarity of a solution that contains 0.220 moles KOH in 0.350 L of solution?

Chemistry

1 answer:

Lera25 [3.4K]2 years ago

5 0

Answer:

0.628 M.

Explanation:

In order to solve this problem we need to keep in mind the definition of molarity:

Molarity = moles / liters

We are given both the number of moles and the volume of solution, meaning we can now proceed to calculate the molarity:

Molarity = 0.220 mol / 0.350 L

Molarity = 0.628 M

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Fill in the coefficients that will balance the following reaction:

vfiekz [6]

6NaC₂H₃O₂ + Fe₂O₃ → 2Fe(C₂H₃O₂)₃ + 3Na₂O

Explanation:

Given equation;

NaC₂H₃O₂ + Fe₂O₃ → Fe(C₂H₃O₂)₃ + Na₂O

To find the coefficient that will balance this we equation, let us set up simple mathematical algebraic expressions that we can readily solve.

Let us have at the back of our mind that, in every chemical reaction, the number of atom is usually conserved.

aNaC₂H₃O₂ + bFe₂O₃ → cFe(C₂H₃O₂)₃ + dNa₂O

a, b, c and d are the coefficients that will balance the equation.

conserving Na; a = 2d

C: 2a = 6c

H: 3a = 9c

O; 2a + 3b = 6c + d

Fe: 2b = c

let a = 1

solving:

2a = 6c

2(1) = 6c

c = $\frac{2}{6} = \frac{1}{3}$

2b = c

b = $\frac{1}{2} x \frac{1}{3}$ = $\frac{1}{6}$

d = 2a + 3b - 6c = 2(1 ) + (3 x $\frac{1}{6}$ ) - (6 x $\frac{1}{3}$ ) = $\frac{1}{2}$

Now multiply through by 6

a = 6, b = 1, c = 2 and d = 3

6NaC₂H₃O₂ + Fe₂O₃ → 2Fe(C₂H₃O₂)₃ + 3Na₂O

learn more:

Balanced equation brainly.com/question/9325293

#learnwithBrainly

6 0

2 years ago

The time necessary for the decay of one- half sample of a radioactive substance is a _____. mass defect daughter half life nucli

Mazyrski [523]

Answer: half life

Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

$t=\frac{2.303}{k}\hspace{1mm}log\frac{x}{a}$

t= time required

k= disintegration constant

x= amount of substance left after time t

a= initial amount of substance

when one half of the sample is decayed, one half of the sample remains and t can be represented as $t_{1/2}$

at $t= t_{1/2}$ , $x=\frac{a}{2}$

$t_{1/2}=\frac{2.303}{k}\hspace{1mm}log\frac{a/2}{a}$

$t_{1/2}=\frac{0.693}{k}$

3 0

3 years ago

Read 2 more answers

Identify the solute with the highest van't Hoff factor. And how do you determine which one is highest?

german

Answer : The correct option is, (A) $AlCl_3$

Explanation :

Van't Hoff factor : It is defined as the ratio of the experimental value of the colligative property to the calculated value of the colligative property.

We can determine the van't Hoff factor by the association and dissociation of the compound.

(A) $AlCl_3$

It is an electrolyte that dissociates to give aluminum ion and chloride ion.

The dissociation of $AlCl_3$ will be,

$AlCl_3\rightarrow Al^{3+}+3Cl^{-}$

So, Van't Hoff factor = Number of solute particles = $Al^{3+}+3Cl^{-}$ = 1 + 3 = 4

(B) $KI$

It is an electrolyte that dissociates to give potassium ion and iodide ion.

The dissociation of $KI$ will be,

$KI\rightarrow K^{+}+I^{-}$

So, Van't Hoff factor = Number of solute particles = $K^{+}+I^{-}$ = 1 + 1 = 2

(C) $CaCl_2$

It is an electrolyte that dissociates to give calcium ion and chloride ion.

The dissociation of $CaCl_2$ will be,

$CaCl_2\rightarrow Ca^{2+}+2Cl^{-}$

So, Van't Hoff factor = Number of solute particles = $Ca^{2+}+2Cl^{-}$ = 1 + 2 = 3

(D) $MgSO_4$

It is an electrolyte that dissociates to give magnesium ion and sulfate ion.

The dissociation of $MgSO_4$ will be,

$MgSO_4\rightarrow Mg^{2+}+SO_4^{2-}$

So, Van't Hoff factor = Number of solute particles = $Mg^{2+}+SO_4^{2-}$ = 1 + 1 = 2

(E) Non-electrolyte

The dissociation non-electrolyte is not possible. So, the Van't Hoff factor will always be, 1.

Hence, the highest van't Hoff factor of solute is, $AlCl_3$

7 0

2 years ago

What is the mass of NaCl required to make 140 grams of a 12% solution of NaCl in water?

Makovka662 [10]

Answer:

C. 17 grams.

Explanation:

∵ mass % = [mass of solute/mass of solution] x 100.

mass of solute (NaCl) = ??? g & mass of solution = 140.0 g.

∴ mass of NaCl = (mass %)(mass of solution)/100 = (12.0)(140.0)/100 = 16.80 g ≅ 17.0 g.

3 0

2 years ago

Read 2 more answers

Which element has the same number of valence electrons as calcium?

kipiarov [429]

Answer:

Barium has the same number of valence electrons as calcium

Explanation:

Valence electrons is the number of electrons of an atom on the outer shell.

Those valence electrons can participate in the formation of a chemical bond (if the outer shell is not closed); in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.

Calcium is an atom, part of group 2, called the alkaline earth metals. The alkaline earth metals have 2 valence electrons.

Sulfur is part of a group 16, called the chalcogens or oxygen family. Those atoms have 6 valence electrons. They can form a bound with atoms of group 2 such as calcium, but do not have the same number of valence electrons.

Potassium is part of group 1, called the alkali metals or lithium family. Those atoms have 1 valence electrons. That means Potassium do not have the same number of valence electrons like calcium.

Neon is part of group 18, the noble gasses. Those are stable atoms, which means they have 8 valence electrons. They do not have the same number of valence electrons like Calcium.

Barium an atom, part of group 2, called the alkaline earth metals. The alkaline earth metals have 2 valence electrons. Calcium is also part of this group.

This means barium has the same number of valence electrons as Calcium.

8 0

2 years ago