8. The protein in a 1.2846-g sample of an oat cereal is determined by a Kjeldahl analysis. The sample is digested with H2SO4, the resulting solution made basic with NaOH, and the NH3 distilled into 50.00 mL of 0.09552 M HCl. The excess HCl is back titrated using 37.84 mL of 0.05992 M NaOH. Given that the proteins in grains average 17.54% w/w N, report the %w/w protein in the sample.

Answers

Answer 1

Answer: The %w/w protein in the sample is 15.2 %

Explanation:

To calculate the number of moles for given molarity, we use the equation:

[tex]\text{Moles of solute}={\text{Molarity of the solution}}\times{\text{Volume of solution (in L)}}[/tex]    

[tex]\text{Moles of} HCl={0.09552\times 50.00}{1000}=0.0047moles[/tex]

[tex]\text{Moles of} NaOH={0.05992\times 37.84}{1000}=0.0023moles[/tex]

[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]  

According to stoichiometry :

1 mole of [tex]NaOH[/tex] require 1 mole of [tex]HCl[/tex]

Thus 0.0023 moles of [tex]NaOH[/tex] will require=[tex]\frac{1}{1}\times 0.0023=0.0023moles[/tex]  of [tex]HCl[/tex]

moles of HCl used = (0.0047-0.0023) = 0.0024

[tex]NH_3+HCl\rightarrow NH_4Cl[/tex]

1 mole of HCl uses = 1 mole of ammonia

Thus 0.0024 moles uses = [tex]\frac{1}{1}\times 0.0024=0.0024moles[/tex] of ammonia

Mass of ammonia= [tex]moles\times {\text {Molar mass}}=0.0024\times 17g/mol=0.0408g[/tex]

17 g of ammonia contains = 14 g of Nitrogen

Thus 0.0408 g of ammonia contains = [tex]\frac{14}{17}\times 0.0408=0.034 g[/tex] of Nitrogen

Now 17.45 g of Nitrogen is present in = 100 g of protein

Thus 0.034 g of Nitrogen is present in =[tex]\frac{100}{17.45}\times 0.034=0.195g[/tex] of protein

Now % w/w of protein = [tex]\frac{0.195}{1.2846}\times 100=15.2\%[/tex]

Thus %w/w protein in the sample is 15.2%

Answer 2

If the proteins in grains average 17.54% w/w N, the % w/w protein in the sample is 15.2 %.

What is Kjeldahl analysis?

It is a process of converting nitrogen present in any compound into ammonium sulfate.

Step1: calculating the moles by the formula of molarity

molarity × volume

M = 0.09552, V =  50.00 mL =0.05 L

Moles of HCl

[tex]0.09552 \times 0.05 = 0.0047\;mol\\[/tex]

Moles of NaOH

[tex]0.05992 \times 0.03784 = 0.0023 \;mol[/tex]

Moles of HCl used is  0.0047 - 0.0023 = 0.0024

Step2: calculating the mass of ammonia

moles × molar mass

[tex]0.024 \times 17\;g/mol = 0.0408\;g[/tex]

Now, 17 grams of ammonia have 14 grams of nitrogen

so, 0.0408 g ammonia have [tex]\dfrac{14}{17} \times 0.0408 = 0.034[/tex]

In 100 g of protein, there is 17.45 g of nitrogen

So, 0.034 g N have [tex]\dfrac{100}{17.45} \times 0.034 = 0.195 g.\\[/tex]

Step3: calculating the % w/w

[tex]\dfrac{0.195}{1.2846} \times 100 = 15.2 \%[/tex]

Thus, the % w/w is 15.2 %

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Related Questions

Buffer sol that contain 1 mol NH4Cl and 1mol NH4OH per liter find PH

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Answer: what

Explanation:

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Answer:

option a. iron,copper, aluminium.

Where are the most reactive nonmetals located on the periodic table?

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The most reactive nonmetals are located in the upper right portion of the periodic table

Which of the following statements about balanced chemical equations is correct?

A.
The products must contain the same numbers and types of atoms as the reactants.

B.
The products must contain the same arrangement of atoms as found in the reactants.

C.
The products must contain the same numbers but not the same types of atoms as the reactants.

D.
The products must contain the same types but not the same numbers of atoms as the reactants.

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Answer:A.

The products must contain the same numbers and types of atoms as the reactants.

Explanation: I think this

Answer:a

Explanation:

what observation helps a poison ivy plant survive in its environment ​

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Hfs got no choice chbx going customers

Complete the balanced molecular chemical equation for the reaction below. If no reaction occurs, write NR after the reaction arrow. Pb ( N O ₃ ) ₂ (aq) + K I (aq) → ☐⁴⁻ ☐³⁻ ☐²⁻ ☐⁻ ☐⁺ ☐²⁺ ☐³⁺ ☐⁴⁺ 1 2 3 4 5 6 7 8 9 0 ☐₁ ☐₂ ☐₃ ☐₄ ☐₅ ☐₆ ☐₇ ☐₈ ☐₉ ☐₀ + ( ) → ⇌ (s) (l) (g) (aq) NR Pb I N O K Reset

Answers

Answer: [tex]Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.

The double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.

The balanced molecular equation is:

[tex]Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]

which statements describe the relationship between the area and the bioversity

Answers

?????????????????????????????????????????

#15 need help don’t understand

Answers

I got B. Lmk if u need explanation

If 13.5 L of nitrogen gas reacts with 17.8 L of hydrogen gas at STP, according to the following reaction, what mass of ammonia would be produced? N2 + 3 H2 --> 2 NH3 Report your answer with proper significant figures, only a number answer is required, no units needed for this form.

Answers

Answer: N5 + H4 and then do 13.5 * 17.8 then solve so 240.3 divided by 9

Your answer is 26.7  Pretty sure

Explanation: (study)

Answer:

Work is all on the paper

why cancer is not a pathogen?​

Answers

Answer:

Because their cells duplicate inside of you not normally!

Explanation:

Hope this helps! Plz mark as brainliest! :)

You find a 1979 copper penny (pre-1982 pennies are pure copper) in the snow and pick it up. How much heat does the penny absorb as it warms from the temperature of the snow, -5.0∘C to the temperature of your body, 37∘C. Assume the penny is pure copper and has a mass of 3.10 g. (The specific heat capacity of copper is 0.385 J/g∘C.)

Answers

Answer:

50.127 J

Explanation:

The following data were obtained from the question:

Initial temperature (T₁) = –5 °C

Final temperature (T₂) = 37 °C

Mass (M) = 3.10 g

Specific heat capacity (C) = 0.385 J/gºC

Heat (Q) absorbed =?

Next, we shall determine the change in temperature. This can be obtained as follow:

Initial temperature (T₁) = –5 °C

Final temperature (T₂) = 37 °C

Change in temperature (ΔT) =?

ΔT = T₂ – T₁

ΔT = 37 – (–5)

ΔT = 37 + 5

ΔT = 42 °C

Finally, we shall determine the heat absorbed. This can be obtained as follow:

Mass (M) = 3.10 g

Specific heat capacity (C) = 0.385 J/gºC

Change in temperature (ΔT) = 42 °C

Heat (Q) absorbed =?

Q = MCΔT

Q = 3.10 × 0.385 × 42

Q = 50.127 J

Thus, the heat absorbed is 50.127 J.

Which molecule or ion below would be expected to have a trigonal planar electron domain geometry?
a. nitrate ion, NO3 1-
b. at least two of these
c. carbon tetrachloride
d. water
e. sulfur dioxide

Answers

Answer:

a. nitrate ion

e. sulfur dioxide

Explanation:

Trigonal planar geometry, is possible, where the combination of atoms or lone pain form a triangle which is is same plane.

Hence, from the given options,

Nitrate ion has a trigonal planar geometry.Carbon tetrachloride has a teterahedral geometrywater has a bent angular geometry.sulfur dioxide has a trigonal planar geometry.

Therefore,

From the given options, the correct answer is -

a. nitrate ion

e. sulfur dioxide

How many Joules of heat are released from a 400g piece of glass that has been cooled
from 28°C to 6°C? The specific heat for this particular type of glass is 0.664 J/g°C.


please show work.

Answers

Answer:

400 × 22 × 0.664 = 5843.2 J

* Urgent Bet no one knows this *

Answers

Answer: The name of the super continent that existed millions of years ago.

Explanation:

Our continents as they exist today were once joined together into a super continent known as Pangea. Over the millennia, the land masses broke off and drifted away creating the location of the continents we know today.

(つ ^‿^ )つ Hey there!

Answer → Is the second answer, The name of the super continent that existed millions of years ago.  

✨Hope this helps!✨

Which feature of a balanced chemical equation demonstrates the law of
conservation of mass?
A. It has the same types of atoms on both sides of the reaction
arrow.
B. It shows the reactants of a chemical reaction to the left of the
reaction arrow.
C. It shows the products of a chemical reaction to the right of the
reaction arrow
D. It has coefficients to show how much of each substance a
chemical reaction uses.
SUBMIT

Answers

Answer:

Another answer is : It has equal numbers of each type of atom in its reactants and products.

Explanation:

I just got it right on A.pex

Given the data from the question, the correct statement is:

It has the same types of atoms on both sides of the reaction arrow (Option A)

What is a chemical equation?

Chemical equations are representations of chemical reactions using symbols and formula of the reactants and products.

The reactants are located on the left side while the products are located on the right side.

Reactants —> Products

The balancing of chemical equations follows the law of conservation of matter which states that matter can neither be created nor destroyed during a chemical reaction but can be transferred from one form to another.

From the law of conservation of matter, it is evident that the same atoms of the element in the reactants are present in the products.

Thus, we can conclude that the correct answer to the question is: It has the same types of atoms on both sides of the reaction arrow (Option A)

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What is climate? What are three things that cause the earths climate?

Answers

Answer:

The climate has been caused by many natural factors including changes in the sun emissions from volcanoes variations in Earth's orbit and levels of carbon dioxide. Global climate change has typically occured very slowly over thousands or millions of years .The three causes of the Earth's climate are

Industrial activitiesAgricultural activitiesDeforestation

these are the causes of the Earth's climate.

Climate is a average weather in a given area for a long period of time is called a climate

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Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose C6H12O6 and oxygen O2 gas. Calculate the moles of water needed to produce 0.075mol of glucose. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits

Answers

Answer: 0.45 moles of water are needed to produce 0.075mol of glucose.

Explanation:

The balanced chemical reaction is:

[tex]6CO_2(g)+6H_2O(l)\rightarrow C_6H_{12}O_6(aq)+6O_2(g)[/tex]

According to stoichiometry :

1 mole of glucose require = 6 moles of [tex]H_2O[/tex]

Thus 0.075 moles of glucose require = [tex]\frac{6}{1}\times 0.075=0.45[/tex] moles of [tex]H_2O[/tex]

0.45 moles of water are needed to produce 0.075mol of glucose.

If a 130-kg car is traveling at a velocity of 23 m/s, what is the kinetic energy of the car?​

Answers

KE = 1/2 * m * v^2
KE = 1/2 * 130 * 23^2
KE = 34385J

Kinetic energy is the amount of energy present in the object due to motion. It is required by the body for action and motion. The kinetic energy of the car is 34385J.

What is kinetic energy?

Kinetic energy is a type of energy that is directly proportional to the mass of the object and the square of the velocity. The formula for the kinetic energy can be given as,

[tex]\rm KE = \dfrac{1}{2}mv^{2}[/tex]

Here,

Mass of the car (m) = 130 kg

Velocity of the car (v) = 23 m/s

Substituting values in the equation:

[tex]\begin{aligned}\rm KE &= \dfrac{1}{2}\rm mv^{2}\\\\&= \dfrac{1}{2}\times 130\times (23)^{2}\\\\&= 34385\;\rm J\end{aligned}[/tex]

Therefore, 34385J is the kinetic energy of the car.

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Please help me!!! this is due now​

Answers

it’s on the opposite side of earth from the sun basically making a sandwich which earth in the middle

NASA pointed the Hubble Space Telescope at a very dark section of sky to see what might be found. The telescope revealed

about 10,000 distant and never-before-seen galaxies. NASA would have to make observations of more than 10,000,000

other sections to study the rest of the sky. If every section of sky also looked out on 10,000 galaxies, about how many

galaxies would exist in the known universe?

100,000,000

1,000,000,000

10,000,000,000

100,000,000,000

Hel

Answers

Answer:

100,000,000,000

Explanation:

Given that :

1 hubble space telescope pointed at 1 section of the sky reveals 10,000 distinct galaxies ;

Number of sections from which observation is to be made = 10,000,000

Number of distinct galaxy per section = 10,000

Number of galaxies that would exist in the known universe :

Total number of galaxies in the known universe :

Number of galaxies per section * number of sections

10,000 * 10,000,000

= 100,000,000,000s

8. Which of the following is TRUE about limiting and excess reactants?
A. The excess reactant will be completely consumed after the reaction is complete
B. The limiting reactant determines the maximum amount of product that can be formed
C. Some of the limiting reactant is left over after the reaction is complete.
D. The reactant that has the largest given mass will be the excess reactant.

Answers

B. The limiting reactant determines the max amount of product that can be formed

The statement which is TRUE about limiting and excess reactants is (B) The limiting reactant determines the maximum amount of product that can be formed.hence the correct option is (B)

What is Limiting reagent ?

A reactant that is completely consumed at the end of a chemical reaction is known as the limiting reagent.

Since the reaction cannot proceed without this reagent, the amount of product that can be produced is constrained.

The reactant that is totally consumed during a reaction, or the limiting reagent, decides when the process comes to an end.

The precise quantity of reactant required to react with another element can be estimated from the reaction stoichiometry.

Therefore, The statement which is TRUE about limiting and excess reactants is (B) The limiting reactant determines the maximum amount of product that can be formed.hence the correct option is (B)

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How many equivalents are in a solution that contains 0.25 moles Mg2+ and 0.50 moles Cl–?

Answers

Answer:

Explanation:

Mg²⁺ is divalent , hence

Molecular weight / 2 = equivalent weight .

.25 moles = 2 x .25 equivalents = .5 equivalents .

Cl⁻ is monovalent so

molecular weight = equivalent weight

.50 mole = .50 equivalent

Total equivalent = .50 of Mg²⁺ + .50 of Cl⁻

= 1 equivalent .

What volume, in milliliters, of a 0.140 M solution of KCl contains 2.65 g of the compound?
Express the volume to three significant figures and include the appropriate units.

Answers

Answer:

Calculate moles KCl: 2.55 g / 74.55 g/mol = 0.0342 moles KCl

Volume KCl = 0.0342 mol X (1 L/0.150 mol) = 0.228 L X 1000 mL/L = 228 mL

Explanation:

Volume=288mL

Given:

Molarity=0.140 M

Mass=2.65 g

To find:

Volume=?

Molar mass of KCl = 74.55 g/mol

Firstly, we need to calculate the number of moles of KCl:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} \\\\\text{Number of moles}=\frac{2.65g}{74.55g/mol} \\\\\text{Number of moles}=0.0355 moles[/tex]

In order to calculate the volume,

[tex]\text{ Volume of KCl} = 0.0342 mol * (1 L/0.150 mol) \\\\\text{ Volume of KCl} = 0.228 L * 1000 mL/L \\\\\text{ Volume of KCl} = 228 mL[/tex]

The volume in mL will be 228mL.

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What are a few ways your body maintains homeostasis?(6th grade and its science)

Answers

Answer: Internal Temperatures. Similarly, the cardiovascular, integumentary (skin and associated structures), respiratory, and muscular systems work together to help the body maintain a stable internal temperature. If body temperature rises, blood vessels in the skin dilate, allowing more blood to flow near the skin's surface.

Explanation:

#12 don’t understand need help significantly

Answers

Answer:

C. 8.80 mol H₂

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Reading a Periodic TableMoles

Stoichiometry

Using Dimensional AnalysisAnalyzing Reactions RxNExplanation:

Step 1: Define

[RxN - Balanced] N₂ (g) + 3H₂ (g) → 2NH₃ (g)

[Given] 100 g 2NH₃

[Solve] moles H₂

Step 2: Identify Conversions

[RxN] 2 mol NH₃ (g) → 3 mol H₂ (g)

[PT] Molar Mass of N - 14.01 g/mol

[PT] Molar Mass of H - 1.01 g/mol

Molar Mass of NH₃ - 14.01 + 3(1.01) = 17.04 g/mol

Step 3: Stoich

[DA] Set up conversion:                                                                                 [tex]\displaystyle 100 \ g \ NH_3(\frac{1 \ mol \ NH_3}{17.04 \ g \ NH_3})(\frac{3 \ mol \ H_2}{2 \ mol \ NH_3})[/tex][DA] Multiply/Divide [Cancel out units]:                                                         [tex]\displaystyle 8.80282 \ mol \ H_2[/tex]

320.0 g of NaCl would contain how many formula units? (Molar mass of
NaCl is 58.44 g/mol) *

Answers

Answer:

Formula unit = 32.9746×10²³

Explanation:

Given:

Mass of NaCl = 320 g

Molar mass of  NaCl = 58.44 g/mol

Find:

Formula unit

Computation:

Formula unit = [Mass of NaCl / Molar mass of  NaCl]Avogadro's number

Formula unit = [320 /58.44]6.022×10²³

Formula unit = 32.9746×10²³

Please help me I’m not sure with that

Answers

What I can’t see the pic ?hhbc639l73773 ghcbhjbch

Answer:

i cant see the picture sorry

Explanation:

1. If 3.2 L of nitrogen monoxide and 4.3 g of oxygen gas are combined, what volume of nitrogen dioxide will be formed? 2NO + 0, -> 2NO,​

Answers

Answer:

[tex]3.2 \div 22.4 = \frac{1}{7} mol \: no[/tex]

[tex]4.3 \div 32 = 0.134mol \: o2[/tex]

Explanation:

NO is limit reactant so:

1÷7×46=6.57 grams of NO2 will form

who know the song genius?​

Answers

Answer:

Me

Explanation:

The one with sia??

What is the estimated life expectancy of tin reserves?

Answers

Answer:

chemical reaction hope this helps ;)

Explanation:

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