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2 years ago

How many moles of solute are contained in a 250 ml solution that has a concentration of.85 m?

1 answer:

3 0

Volume = 250 mL in liters : 250 / 1000 => 0.25 L

Molarity = 0.85 M

Number of moles:

n = M x V

n = 0.85 x 0.25

n = 0.21 moles

Choice B

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Limit sodium intake to less than ____________ per day. Limit saturated fat intake to less than ____________ of daily kilocalorie

kotykmax [81]

Answer:

Limit sodium intake to less than 2,300mg per day. Limit saturated fat intake to less than 10% of daily kilocalories. Limit intake of added sugars to less than 5% of daily kilocalories. Limit intake of alcohol to less than 3 drinks per day for men or less than 2 drinks per day for women.

Explanation:

The human body has been designed such that there are dietary requirements and benefits these intakes give the body. However, excess consumption of certain foods, could be far more detrimental both on the short and long run.

Sodium is majorly consumed in the form of salt (Sodium chloride). When eaten in the right quantity, it serves as an electrolyte which maintains fluid balance in the body however, when taken in excess, it pulls too much fluid, leading to high blood pressure. The recommended salt intake therefore, is less than 2,300mg daily.

Saturated fat when consumed, is a good source for the body to convert diet to energy, keeping the blood sugar levels constant. Lard, fatty meats are examples of saturated fat. However, when consumed in large amounts, saturated fats can cause cholesterol build up in blood vessels, increasing the risk of heart disease. Its intake should therefore be limited to less than 10% of daily kilocalories.

Added sugars are sources of energy to the body however, when taken in large amounts, could impede normal metabolism in the body. Added sugars should be restricted to less than 5% of daily kilocalories in diet.

Alcohol intake such as in wine, when done in moderation, has been shown to reduce the risk of heart diseases. However, when taken in excess, tolerance builds and exposes the body to the risk of conditions such as liver disease, alcohol use disorder.

4 0

3 years ago

A sample of 211 g of iron (III) bromide is reacted with

Alisiya [41]

FeBr₃ ⇒ limiting reactant

mol NaBr = 1.428

<h3>Further explanation</h3>

Reaction

2FeBr₃ + 3Na₂S → Fe₂S₃ + 6NaBr

Limiting reactant⇒ smaller ratio (mol divide by coefficient reaction)

FeBr₃

211 g of Iron (III) bromide(MW=295,56 g/mol), so mol FeBr₃ :

$\tt n=\dfrac{mass}{MW}\\\\n=\dfrac{211}{295,56}\\\\n=0.714$

Na₂S

186 g of Sodium sulfide(MW=78,0452 g/mol), so mol Na₂S :

$\tt n=\dfrac{186}{78.0452}=2.38$

Coefficient ratio from the equation FeBr₃ : Na₂S = 2 : 3, so mol ratio :

$\tt FeBr_3\div Na_2S=\dfrac{0.714}{2}\div \dfrac{2.38}{3}=0.357\div 0.793$

So FeBr₃ as a limiting reactant(smaller ratio)

mol NaBr based on limiting reactant (FeBr₃) :

$\tt \dfrac{6}{3}\times 0.714=1.428$

6 0

2 years ago

Which of the following groups have seven valence electrons and are very reactive?

valina [46]

Answer:

Column 17 halogens

Explanation:

To answer the question we need to know the following;

What are valence electrons?

Valence electrons are outermost electrons in the outermost energy level of an atom of any element.

What are halogens?

Halogens are group 7 elements that have seven valence electrons. They include, chlorine, fluorine, iodine, etc

What is the reactivity of halogens?

Halogens are the most reactive non-metals in the periodic table. They react by gaining one electron to attain a stable configuration.

4 0

2 years ago

Read 2 more answers

A reaction has a forward rate constant of 2.3 × 106 s-1 and an equilibrium constant of 4.0 × 108. what is the rate constant for

avanturin [10]

Answer is: 5,75·10⁻¹.
Kf = 2,3·10⁶ 1/s.
K = 4,0·10⁸ 1/s.
Kr = ?
Kf - forward rate constant.
K - equilibrium constant.
Kr - reverse rate constant.
Since both Kf and Kr are constants at a given temperature, their ratio is also a constant that is equal to the equilibrium constant K.
K = Kf/Kr.
Kr = Kf/K = 2,3·10⁶ 1/s ÷ 4,0·10⁸ 1/s = 5,75·10⁻¹.

5 0

2 years ago

You bought a new fish aquarium with the dimensions of 55 cm x 100 cm x 80 cm. what volume of water should you put in it? Show yo

harina [27]

Since its volume you do what it says 55 cm x 100 cm x 80cm and do 100 x 50 which is 5,000. then 5,000 x 80 which is 40,000. sorry i cant show work on here.

8 0

3 years ago