Breve resumen de que es volumen

A substance undergoes a change. Which of the following indicates that the change was a chemical change?

hoa [83]

The answer is A. The substance changed shape.

There you go!

4 0

3 years ago

What are the symbols (in order) for hydrogen, sodium and nitrogen?

Ulleksa [173]

Answer:

H, Na, N

Explanation:

7 0

2 years ago

Read 2 more answers

determine mass of water formed when 12.5 L NH3(at298K and 1.50atm) is reacted with 18.9L of O2 (at 323K and 1.1atm)

sasho [114]

The mass of water formed is

calculation

Use the ideal gas equation to calculate the moles of NH3 and O2

that is Pv= n RT

where; P= pressure,

V= volume,

n = number of moles,

R=gas constant = 0.0821 l .atm/ mol.K

make n the formula of the subject by diving both side by RT

n = PV /RT

The moles of NH3

n= (1.50 atm x 12.5 L) /( 0.0821 L. atm /mol.k x 298 K) =0.766 moles

The moles of O2

=(1.1 atm x 18.9 L) / ( 0.0821 L. atm/ mol.k x 323 K) = 0.784 moles

write the reaction between NH3 and O2

4 NH3 + 5 O2 →4 No +6H2O

from equation above 0.766 moles of NH3 reacted to produce

0.766 x 6/4 =1.149 moles of H2O

0.784 moles of O2 reacted to produce 0.784 x 6/5=0.9408 moles of H20

since O2 is totally consumed, O2 is the limiting reagent and therefore the moles of H2O produced= 0.9408 moles

mass of H2O = moles x molar mass

from periodic table the molar mass of H2O = (1 x2)+16= 18 g/mol

mass = 18 g/mol x 0.9408 moles= 16.93 grams

3 0

3 years ago

Write the balanced NET IONIC equation for the reaction that occurs when ammonium nitrate and potassium hydroxide are combined. N

vova2212 [387]

Answer:

Net Ionic equation

NH₄⁺ + OH⁻ → NH₃ + H₂O

Option B is correct.

Weak Acid Strong Base

Check Explanation for the extent of the reaction.

Explanation:

Ammonium nitrate = NH₄NO₃

Potassium Hydroxide = KOH

Ammonium salts combine with alkalis to liberate NH₃ and form water.

The two reactants combine to give

NH₄NO₃ + KOH → KNO₃ + NH₃ + H₂O

In ionic form,

- NH₄NO₃ exists as NH₄⁺ and NO₃⁻

- KOH exists as K⁺ and OH⁻

- KNO₃ as K⁺ and NO₃⁻

And NH₃ and H₂O stay as they are, as per covalent compounds.

So, we have

NH₄⁺ + NO₃⁻ + K⁺ + OH⁻ → K⁺ + NO₃⁻ + NH₃ + H₂O

Eliminating the ions that exist on both sides, we have the net ionic equation to be

NH₄⁺ + OH⁻ → NH₃ + H₂O

which shows that this reaction is essentially a neutralization reaction in which the Bronsted Lowry acid, NH₄⁺, loses its proton to the base, OH⁻ and gives conjugate base, NH₃ and conjugate acid, H₂O.

This reaction is classified as a Weak acid versus Strong Base reaction as NH₄⁺ is from a Weak acid and OH⁻ is from a strong base.

Since this reaction is between a Weak base and a strong acid, the ionization isn't expected to be 100%, Hence, the extent of this reaction will be any option that is not 100%, a couple pieces of information might be required for the correct estimate, but above 50% seems correct.

Hope this Helps!!!

8 0

3 years ago

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