3. Which of the following could be characterized as macronutrients in food?

What is the molarity of a solution that contains 224 grams of KOH in 2<br> liters of solution?

adelina 88 [10]

Answer:

$\boxed {\boxed {\sf 2 \ M \ KOH}}$

Explanation:

Molarity is a measure of concentration in moles per liter.

<h3>1. Grams to Moles </h3>

The first step is to convert the amount of grams given to moles. The molar mass is used. This found on the Periodic Table and it's the same value as the atomic mass, but the units are grams per mole.

We have 224 grams of KOH. Look up the molar masses for the individual elements.

Potassium (K): 39.098 g/mol
Oxygen (O): 15.999 g/mol
Hydrogen (H): 1.008 g/mol

Since the compound's formula has no subscripts, 1 formula unit has 1 atom of each element. We can simply add the molar masses together to find KOH's molar mass.

KOH: 39.098 + 15.999 + 1.008=56.105 g/mol

Use this number as a ratio.

$\frac {56.105 \ g\ KOH}{1 \ mol \ KOH}$

Multiply by the value we are converting: 224 g KOH

$224 \ g \ KOH *\frac {56.105 \ g\ KOH}{1 \ mol \ KOH}$

Flip the ratio so the units of grams KOH cancel.

$224 \ g \ KOH *\frac {1 \ mol \ KOH}{56.105 \ g\ KOH}$

$224 *\frac {1 \ mol \ KOH}{56.105}$

$\frac {224}{56.105} \ mol \ KOH$

$3.992514036 \ mol \ KOH$

<h3>2. Calculate Molarity </h3>

Remember molarity is moles per liter.

$molarity = \frac{moles}{liters}$

We just calculated the moles and we know there are 2 liters of solution.

$molarity = \frac{ 3.992514036 \ mol \ KOH}{ 2 \ L}$

$molarity= 1.996257018 \ mol \ KOH/ L$

<h3>3. Round and Convert Units </h3>

First, let's round. The original values have 3 and 1 significant figures. We go with the lowest number: 1. For the number we found, that is the ones place.

1.<u>9</u>96257018

The 9 in the tenths place tells us to round to 1 up to a 2

$2 \ mol \ KOH/ L$

Next, convert units. 1 mole per liter is equal to 1 molar or M.

$2 \ M \ KOH$

The molarity of the solution is <u>2 M KOH</u>

6 0

3 years ago

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Which phase change is an example of an exothermic process?

liberstina [14]

its solid to liquid

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3 years ago

When designing an engineering solution, certain criteria and constraints must be considered. Criteria are the features of the de

kondor19780726 [428]

Answer:

The criteria listed in order of importance are;

1) To be inflated in the event of a collision in order to protect the occupants of the front of the vehicle

2) To be able to withstand the load of the breaking force of the occupants in the front seat of the vehicle during a collision

3) To be relatively tough so as to resist being torn on impact with a sharp object

The constraints listed in order of importance are;

1) How is the model design able to sense a collision that requires the airbag to be inflated

2) The uncertainty of the load the airbag will withstand upon collision

3) The possible hazard that could be caused by the gas used to inflate the airbag

4) The usage/interaction tendency between the vehicle occupant and the airbag system

Explanation:

In order to produce an effective design, it is important to be able to foresee the possible deficiencies of an idea so as to be able to mitigate the problems before an actual incident happens.

5 0

4 years ago

Sterling silver contains silver and copper metals. If a sterling silver chain contains 33.3 g of silver and 2.70 g of copper, wh

marusya05 [52]

Answer:

7.5 % of Ag

Explanation:

Total mass of sterling silver chain is:

Mass of silver + Mass of copper

33.3 g Ag + 2.70g of Cu = 36 g

% of Silver is (mass of silver / total mass) . 100 →

(2.70 g / 36 g) . 100 → 7.5%

7 0

3 years ago

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Reactivity and flammability are are examples of properties.

nika2105 [10]

Answer:

they are eamples of chemical properties

Explanation:

flammibility is the chemical makeup of the element that makes it flamable and reactivitie is the chemical makeup of an element that is able to reacte to another element

3 0

3 years ago