A sample was then prepared containing 14.00 mL of coffee and 8.00 mL of 4.80 ppm Li , and diluted to a 50.00 mL total volume. The ratio of the internal standard signal to the analyte signal in the unknown sample was found to be 0.840/1.000 (Li signal/Na signal). Determine the unknown concentration of Na in the coffee sample.

Answers

Answer 1

Answer:

The right answer is "[tex][Na^+]=5.57 \ ppm[/tex]".

Explanation:

The given values are:

[tex]\frac{A_s}{A_{coffee}} =\frac{0.840}{1.000}[/tex]

According to the question,

The concentration of standard will be:

=  [tex]\frac{7.80}{50.00}\times 4.80[/tex]

=  [tex]0.156\times 4.80[/tex]

=  [tex]0.748 \ ppm[/tex]

Coffee after dilution,

⇒  [tex]\frac{A_{coffee}}{C_{coffee}} =F\times \frac{A_s}{C_s}[/tex]

or,

⇒  [tex]C_{coffee}=\frac{A_{coffee}}{A_s}\times \frac{C_s}{F}[/tex]

On substituting the values, we get

⇒               [tex]=\frac{1.000}{0.840}\times \frac{0.748}{1.68}[/tex]

⇒               [tex]=1.191\times 1.3104[/tex]

⇒               [tex]=1.561 \ ppm[/tex]

hence,

In unknown sample, the concentration of coffee will be:

=  [tex]1.561\times \frac{50}{14}[/tex]

=  [tex]\frac{78.05}{14}[/tex]

=  [tex]5.57 \ ppm[/tex]


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Answer:

Covalent

Explanation:

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What is the percent by mass of aspartame in iced tea that has 0.75 g of aspartame in 250 g of water?

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Answer:0.30%

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Do frogs start their life cycle on land or water?

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The answer is water because they lay eggs in water

Draw the most stable form of the major product in the reaction. 2 equivalents of an ester react with N a O C 2 H 5, followed by H 3 O plus and C 2 H 5 O H. The ester is a carbonyl bonded to a 3 carbon chain and O C H 2 C H 3.

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Answer:

See answer below

Explanation:

This is a Claisen condensation. In the picture below you have the mechanism and final product.

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two differences between weather and climate
subject-science


Answers

Answer:

weather- rain, hail, snow, sunny, dry, etc.

climate- warm, cold, humid, dry, etc.

Explanation:

The difference if weather and climate is that climate is the way the temperature is,  whether it's warm, cold, humid, dry. While weather is the state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain, etc.

Which food is the most complete source of amino acids?

A. Bread
B. Fruit
C. Butter
D. Meat

Answers

Answer:

D.Meat

Explanation:

Meat-Most animals proteins are considered complete and high-quality.This includes red meat, poultry,and dairy products.

Amino acids are the molecules that make the protein and are essential nutrients. Meat is the best source that will have amino acids. Thus, option D is correct.

What are amino acids and proteins?

Amino acids are the building blocks that make the macromolecule, a protein required for functioning, strength, and activities of the body. Amino acid-containing foods like eggs, meat, and soybeans are rich in proteins.

Amino acids and proteins are essential for body growth and repair that can be gained from poultry sources like eggs, meat, fish, cheese, quinoa, beans, etc. Bread, fruits, and butter are rich in carbohydrates.

Therefore, option D. meat is rich in amino acids.

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A student is asked to determine the identity of an unknown metal. The student decides to use a calorimetry experiment to find the specific heat. The student will use this as a means of identifying the metal Which of the following measurements cannot made using standard laboratory equipment?
A mass of water
B temperature of metal
с heat lost by metal
D mass of metal​

Answers

Answer:

Temperture of the medal

Explanation:

Bc ik

PLEASE PLEASE HELP!!!!

Approximately what mass of potassium nitrate will eventually precipitate from a supersaturated solution containing 19 grams of the solute in 28 grams of water at 40C°?

Answers

A supersaturated solution contains more solute at a given temperature than is needed to form a saturated solution.

Increased temperature usually increases the solubility of solids in liquids.

For example, the solubility of glucose at 25 °C is 91 g/100 mL of water. The solubility at 50 °C is 244 g/100 mL of water.

If we add 100 g of glucose to 100 mL water at 25 °C, 91 g dissolve. Nine grams of solid remain on the bottom. We have a saturated solution.

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What is the name of Na

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sodium
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Cómo escribir el símbolo Theta

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Para escribir el símbolo theta, presione 03B8 + Alt + X.
En ingles The theta symbol

4. Which of the following process is NOT part of wool extraction?
(a) Shearing (b) Scouring (c) Sorting
(d) Reeling​

Answers

Answer:

Reeling is the only process not listed.

The correct answer is option D: Reeling​.

Wool is obtained from sheep. The wool so obtained is processed according to the following flow chart;

Shearing → Scouring → Sorting → Dyeing → Straightening, Rolling and Combing

Shearing is the removal of the fleece and thin skin of the sheep. Scouring is the process of washing the hair to remove grease, dust, and dirt. Sorting is the process of differentiating the fibers.

Hence, reeling is not a process in wool extraction.

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What is The metric unit for volume ?

Answers

Answer:

milliliters

Explanation:

Is going to be milliliters because in the metric system of measurement,the most common unit of volume are milliliters and liters

Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory as a primary standard. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP. If 31.0 mL of a barium hydroxide solution are needed to neutralize 1.37 grams of KHP, what is the molarity of the barium hydroxide solution

Answers

Answer:

0.1082M of Barium Hydroxide

Explanation:

KHP reacts with Ba(OH)2 as follows:

2KHP + Ba(OH)2 → 2H2O + Ba²⁺ + 2K⁺ + 2P²⁻

Where 2 moles of KHP reacts per mole of barium hydroxide

To solve this question we must find the moles of KHP in 1.37g. With these moles and the reaction we can find the moles of Ba(OH)2 and its molarity using the volume of the solution (31.0mL = 0.0310L) as follows:

Moles KHP -Molar mass: 204.22g/mol-

1.37g * (1mol / 204.22g) = 0.006708 moles KHP

Moles Ba(OH)2:

0.006708 moles KHP * (1mol Ba(OH)2 / 2mol KHP) =

0.003354 moles Ba(OH)2

Molarity:

0.003354 moles Ba(OH)2 / 0.0310L =

0.1082M of Barium Hydroxide

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Answers

Answer:

evaporation is the process

Answer:

Evaporation

Explanation:

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Therefore, the final answer is evaporation.

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Answers

Answer:

ΔG° = ΔH° - TΔS°

ΔG° = 25.22-(201 )(0.08448)

ΔG° = 8.24 kJ/mol

The standard free energy is obtained as 8.2  kJ/mol.

We know that; ΔG° = ΔH° - TΔS° where;

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ΔG° =25.22 kJ/mol - (201 K * 84.48 J/mol K)

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A student needs to dilute a 0.25 M Pb(NO3)2 solution to make 73.0 mL of 0.13 M Pb(NO3)2 . Set up the calculation by placing the values with the correct units into the equation. Then, calculate the volume, in milliliters, of the 0.25 M Pb(NO3)2 solution that is needed.

Answers

Answer: Volume of 0.25 M solution is 38 ml

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Answers

Answer:

The ration of molar concentration is "2.5".

Explanation:

The given values are:

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= [tex]1.03 \ g/cm^3[/tex]

Net pressure,

= [tex]2.00 \ atm[/tex]

Increase in pressure,

= [tex]1.00 \ atm[/tex]

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=  [tex]\frac{15 \ m}{10}\times 1 \ atm +1 \ atm[/tex]

=  [tex]1.5\times 1+1[/tex]

=  [tex]1.5+1[/tex]

=  [tex]2.5 \ atm[/tex]

hence,

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=  [tex]\frac{(\frac{n}{V})_{15m} }{(\frac{n}{V})_{surface} }[/tex]

or,

=  [tex]\frac{P}{P_s}[/tex]

=  [tex]\frac{2.5}{1}[/tex]

=  [tex]2.5[/tex]

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the answer would be F

The blank
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I think it’s “number” and “type”

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Answer:Law of inertia, also called Newton's first law, postulate in physics that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force
If the forces are balanced , the object will make no movement. Enjoy :)

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SUR

Answers

Answer:

B

Explanation:

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Answer:

B. The mixture of one substance dissolved in another

Explanation:


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Answer:

frog-snake+-Eagle

Explanation:

___&&&-(_(-7&&((-&(_((-_(_-8&:"&&7+_&(&_

When a lead acid car battery is recharged by the alternator, it acts essentially as an electrolytic cell in which solid lead(II) sulfate PbSO4 is reduced to lead at the cathode and oxidized to solid lead(II) oxide PbO at the anode. Suppose a current of 17.0A is fed into a car battery for 15.0 seconds. Calculate the mass of lead deposited on the cathode of the battery. Be sure your answer has a unit symbol and the correct number of significant digits.

Answers

Answer:

0.273504 grams

Explanation:

Charge Deposited = Current ×Time

q=It

Given: I= 17.0A, t= 15.0 seconds

Q= 17×15= 255 C

Since, 1 mole contains 96500C of charge deposition

Therefore, number of moles = 255/96500 = 0.00264 moles

Moreover, since Pb changes to Pb2+,

Hence number of moles of Pb deposited = 0.00264/2

= 0.00132

Also, Molar mass of Lead = 207.2 gm/mol

Therefore, the mass of lead deposited = 0.00132×207.2 = 0.273504 grams

.

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2.
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Answer:

2. Hydrogen Bonds

Explanation:

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The primary forces of attraction between water molecules in H₂O (I) are hydrogen bonds.

What kind of chemical bonding is present in water molecule?

Hydrogen bonding is present in water molecule due to which it exhibits an excellent property of adhesion to itself and to other substances.The hydrogen bonding is a result of electrostatic forces of attraction which are generated by the difference in charge between slightly positive hydrogen ions and slightly negative other ions.

In case of water,hydrogen bonds are formed  between neighboring  hydrogen and oxygen atoms  of the nearby water molecules.The attraction between water molecules itself results in a formation of a bond called as a hydrogen bond.  

It is a type of covalent bond which is formed  between hydrogen and oxygen atoms as one oxygen atom  shares its two electrons with two hydrogen atoms .The positive charge  of one hydrogen atom associates with negative charge of  oxygen atom.These are weak interactions  which are formed between a hydrogen atom each with a partial positive charge and an oxygen atom which is more electronegative than hydrogen.

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Which of these is a good conductor?
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Metal is a good conductor of heat therefore it is the answer

→ Search the internet to understand the reaction between (Zno) & (HNO3).
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b) Describe what would happen if the student kept adding zinc oxide to the nitric acid
after the reaction between the acid and metal oxide was complete.

Answers

Answer:

See Explanation

Explanation:

The equation of the reaction is;

ZnO(s) + 2HNO3(aq) --------> Zn(NO3)2(aq) + H2O(l)

a) When you first add ZnO to aqueous HNO3, the powder dissolves as it mixes with the acid.

b) If the student keeps on adding more ZnO powder to the HNO3 after the  reaction between the acid and metal oxide was complete, the powder will no longer dissolve in the acid. At this point, the reaction has attained equilibrium.

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Answers

Answer:

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Explanation:

brainliest pls

Which of the following contains the least amount (number) of molecules?

Group of answer choices

5.0 g O2


5.0 g H2O


5.0 g N2


5.0 g CO2

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5.0 g N2
Has to be correct

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Answer:

the mass of one spoonful of sugar to nearest gram is 10g

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