A 2.74-g sample of a substance suspected of being pure gold is warmed to 72.1 oC and submerged into 15.2 g of water initially at 24.7 oC. The final temperature of the mixture is 26.3 oC. What is the heat capacity of the substance? Could the substance be pure gold?
(The specific heat capacity of water is 4.184 J/g oC)
J/g oC (Round to three significant digits)
Look up the specific heat capacity of gold.
Could the unknown substance be pure gold? Write yes or no in the following box:
1. The specific heat capacity of the sample of gold obtained is 0.81 J/gºC
2. The substance is not pure gold
1. How to determine the specific heat capacity of gold From the question given above, the following data were obtained:Mass of gold (M₉) = 2.74 gTemperature of gold (T₉) = 72.1 °CMass of water (Mᵥᵥ) = 15.2 g Temperature of water (Tᵥᵥ) = 24.7 °C Equilibrium temperature (Tₑ) = 26.3 °C Specific heat capacity of the water (Cᵥᵥ) = 4.184 J/gºC Specific heat capacity of gold (C₉) =?The specific heat capacity of the sample of gold can be obtained as follow:
Heat loss = Heat gain
M₉C₉(M₉ –Tₑ) = MᵥᵥC(Tₑ – Tᵥᵥ)
2.74 × C₉(72.1 – 26.3) = 15.2 × 4.184 (26.3 – 24.7)
C₉ × 125.492 = 101.75488
Divide both side by 125.492
C₉ = 101.75488 / 125.492
C₉ = 0.81 J/gºC
2. How to determine if the substance is pure Specific heat capacity of gold calculated = 0.81 J/gºC Specific heat capacity of pure gold = 0.13 J/gºCFrom the above we can conclude that the substance is not pure gold since the calculated and standard value of the specific heat capacity of the gold sample is not the same
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How many grams are in 2.3 moles of Aluminum
Answer:
62.1 gram
Explanation:
Al molar mass = 27 g/mol
mass = molar mass × no of moles
= 27 × 2.3 = 62.1 gram
For the chemical reaction
2 NaOH + H2SO4 — Na2SO4 + 2H2O
how many moles of sodium sulfate will be produced from 28.3 g of sodium hydroxide?
The number of mole of sodium sulphate, Na₂SO₄ that will be produced from 28.3 g of sodium hydroxide, NaOH is 0.35 mole
How to determine the mole of NaOH Mass of NaOH = 28.3 gMolar mass of NaOH = 40 g/mol Mole of NaOH =?Mole = mass / molar mass
Mole of NaOH = 28.3 / 40
Mole of NaOH = 0.7075 mole
How to determine the mole of Na₂SO₄ produced2NaOH + H₂SO₄ —> Na₂SO₄ + H₂O
From the balanced equation above,
2 moles of NaOH reacted to produce 1 mole of Na₂SO₄.
Therefore,
0.7075 mole of NaOH will react to produce = (0.7075 × 1) / 2 = 0.35 mole of Na₂SO₄
Thus, 0.35 mole of Na₂SO₄ was obtained from the reaction
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What's meant by chemistry
Answer: Chemistry is the properties, composition, and structure of elements and compounds, how they can change, and the energy that is released or absorbed when they change.
Explanation:
Answer:
The scientific study of the structure of substances and what happens to them in different conditions or when mixed with each other is known as Chemistry.
Please mark my answer the brainliest and rate me 5 star and follow me.how does temperature affect solubility
Answer:
The increase in kinetic energy that comes with higher temperatures allows the solvent molecules to more effectively break apart the solute molecules that are held together by intermolecular attractions.
Explanation:
Solubility is affected by temperature due to heatness.
SOMEONE PLEASE HELP I WILL Mark u BRAINLIST
Answer:
answer 7.4 atm
Explanation:
i did this and got it correct
HELP PLZ!!! A sample contains only the compound CaCl2 and water. When it is dried, its weight decreases from 5.00g to 4.24g. What is the mass percentage of water in the original sample? Round to three significant figures.
Answer:is 15.2%
Explanation:
Got it wrong and this the correct answer it told me
The percentage of water in the original sample is 15.2 %.
From the information provided in the question;
Weight of the wet sample = 5.00g
Weight of the dried sample = 4.24g
Loss in mass = 5.00g - 4.24g = 0.76 g
percentage of water in the original sample = Difference in mass between wet and dry sample/ mass of wet sample × 100/1
Hence, when we substitute values;
percentage of water in the original sample = 0.76 g/5.00g × 100/1
percentage of water in the original sample = 15.2 %
So, the percentage of water in the original sample is 15.2 %.
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Pure gold has a density of 19.32g/cm^3. You find a gold ring with a mass of 6g and a volume of 0.31cm^3.is this ring pure gold?
Answer:
Yes, this ring is pure gold because when we divide the mass by the volume we get our density for the ring, which comes out to about 19.32.
Explanation:
squence the steps in constructing and interpreting an electron dot diagram
At 600. K how many moles of gas are in a 1.00 L cylinder at atmospheric pressure?
Answer:
0.02moles
Explanation:
To answer this question, the general gas law equation is used. The General gas law is:
Pv = nRT
Where; P = standard atmospheric pressure (1 atm)
V = volume (L)
n = number of moles
R = Gas law constant
T = Temperature
For this question; volume = 1.00L, atmospheric pressure (P) = 1 atm, R = 0.0821 L-atm / mol K, T = 600K, n = ?
Therefore; Pv = nRT
n = PV/RT
n = 1 × 1/ 0.0821 × 600
n = 1/49.26
n = 0.0203moles
Hence, there are 0.02 moles of gas.
The number of mole of the gas present in the cylinder is 0.02 mole
From the question given above, the following data were:
Temperature (T) = 600 K
Volume (V) = 1 L
Pressure (P) = 1 atm
Number of mole (n) =?The number of mole of the gas present in the cylinder can be obtained by using the ideal gas equation (PV = nRT) as illustrated below:
Temperature (T) = 600 K
Volume (V) = 1 L
Pressure (P) = 1 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Number of mole (n) =? PV = nRT1 × 1 = n × 0.0821 × 600
1 = n × 49.26
Divide both side by 49.26
[tex]n = \frac{1}{49.26}\\\\[/tex]
n = 0.02 moleThus, 0.02 mole of the gas is present in the cylinder.
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What is the slope of the line on the graph?
Answer:
6
Explanation:
slope= [tex]\frac{rise}{run}[/tex]
slope=[tex]\frac{6}{1}[/tex]
slope=6
Answer:
its one half
Explanation:
i learned this last week
What are the basis of making symbols of an element?
Each element is given its own chemical symbol, like H for hydrogen or O for oxygen. Chemical symbols are usually one or two letters long. Every chemical symbol starts with a capital letter, with the second letter written in lower case. For example, Mg is the correct symbol for magnesium, but mg, mG and MG are wrong...
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Determine the subunit composition of a protein from the following information:
a. Molecular mass by gel filtration: 200 kD
b. Molecular mass by SDS-PAGE: 100 kD
c. Molecular mass by SDS-PAGE with 2-mercaptoethanol: 40 kD and 60 kD
Answer:
Explanation:
The protein comprises of two 60-kD polypeptides and two 40-kD polypeptides. Each one of the 40-kD chains has a disulfide-bond which is directly bonded to a 60-kD chain.
The 100-kD units attach noncovalently to produce a protein with a molecular mass of 200 kD. The interaction among the different subunits in the protein is not affected by the Gel filtration chromatography.
Hence, the protein seems to be 200 kD in size. When SDS-PAGE takes place samples are being subjected to heat and therefore undergoing denaturation conditions. The aftermath effect of this causes disorganization in the 100 kD units.
However, the reducing agent (BME) main task is the reduction of disulfide bonds in a protein.
It implies that BME is responsible for the reduction between the R1-S-S-R2 bond between 40 kD and 60 kD to R1-SH and R2-SH, resulting in seperate proteins.
the # molecules in 52.1 grams of NH4OH
Answer:
Explanation:
Hey there!
From question;
The molecular mass of NH₄OH is 35.
Avogadro number = 6.023*10²³ molecules.
Then,
From mole concept,
Molecular mass = Avogadro number
So, 35 grams contains 6.023*10²³ molecules.
1 gram contains [tex]\frac{ 6.023*10^{23} }{35}[/tex] molecules.
52.1 grams contains [tex]\frac{6.023*10^{23} }{35} *52.1[/tex] molecules.
Therefore, 52.1 grams contains 8.96*10²³ molecules.
Hope it helps!
What was the major organic product obtained when propanal was heated with a catalytic amount of KOH in water
Answer:
Commercially, 2-methylpentenal is synthesized by the aldol condensation of propanal in the presence of liquid base like KOH or NaOH in stoichiometric amount,,. Under optimum reaction conditions, 99% conversion of propanal is achieved with 86% selectivity of 2-methylpentenal using liquid base.
Explanation:
hope this helps
Answer:
HMM, what the person above said.
Calculate the molarity of solution of "sodium sulfate" that contains 5.2 grams sodiums sulfate diluted to 500mL
Taking into account the definition of molarity, the molarity of solution of sodium sulfate is 0.0732 [tex]\frac{moles}{liter}[/tex].
Definition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Molarity of solution of sodium sulfate.In this case, you have:
number of moles of sodium sulfate= [tex]5.2 grams\frac{1 mole}{142 grams} = 0.0366 moles[/tex] (being 142 g/mole the molar mass of sodiums sulfate)volume= 500 mL= 0.5 L (being 1000 mL= 1 L)Replacing in the definition of molarity:
[tex]Molarity=\frac{0.0366 moles}{0.5 L}[/tex]
Solving:
Molarity= 0.0732 [tex]\frac{moles}{liter}[/tex]
Finally, the molarity of solution of sodium sulfate is 0.0732 [tex]\frac{moles}{liter}[/tex].
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A rock has been placed in water. The mass of the rock is 20 g. What is the rock's density?
g/mL
Answer:
0.67 g mL-1
Explanation:
Every time a problem asks you to find the density of a substance, your goal will essentially be to determine the mass of one unit of volume of said substance.
lead 2 nitrate and potassium iodide net ionic equation
Answer:
Pb2+(aq) + l+(aq) ------------pbl2(s) net ionic equation
Explanation:
Pb(NO3)2(aq) + kI(aq)------------PbI2(s) + kNo3(aq)
Pb2+ (aq)No3-(aq) + k+(aq) l-(aq) ______PbI2(s) + k+(aq) + NO32+(aq)
Pb2+(aq) + I-(aq). ------------Pbl2(s)
How many moles of Co would be required to react with 6.14m of P4
The number of moles of Co that would be required to react with 6.14 moles of P4 would be 36.84 moles
Stoichiometric calculationsFrom the equation of the reaction:
6Co + P4 → 2Co3P2
For every 1 mole of P4, 6 moles of Co is required for complete reaction.
Thus, the mole of Co that would be needed for 6.14 moles of P4 would be:
6 x 6.14 = 36.84 moles
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Mg + AgNO3 MgNO3 + Ag
How many grams of magnesium are needed to produce 5.0 moles of silver
Answer:
539.35 g
Explanation:
molar mass of Mg = moles of Ag * molar mass of Ag
x = 5 * 107.87
x = 539.35 g
Write the name for each of the following chemical formulas.
d. P3N5 (for doping semiconductors)
Answer:
Triphorphorus Pentanitride
Explanation:
since there are three phosphorus use the prefix tri-, since there are five nitrogen use the prefix penta. tri=3, penta=5. then add a suffix -ide to the end of nitrogen. that will give you triphosphorus pentanitride.
How do you know what’s inside of an atom
Answer:
microscope
Explanation:
What is the rate law for the following mechanism? Step 1: A + B = C (fast) Step 2: B + C=D (slow) Rate = k*
Answer:
The rate law is
rate
=k[A][B]^2
What is the density at 27 °C of 28.0 milliliters of a liquid that has a mass of 4.05 grams?
Answer:
The answer is 0.14 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 4.05 g
volume = 28 mL
We have
[tex]density = \frac{4.05}{28} \\ = 0.1446428571...[/tex]
We have the final answer as
0.14 g/mLHope this helps you
If the molecular weight of horseradish peroxidase is about 44,000 g/mol, how many moles of enzyme are used per mole of vanillin?
What is when the molecular weight of horseradish peroxidase is about 44,000 g/mol, The number of moles of the enzyme used per mole of vanillin is
ME=289.188moles
What is the number of moles of the enzyme used per mole of vanillin?Generally, the equation for the moles of the enzyme is mathematically given as
[tex]ME=\frac{molecular weight}{vanilin MW}[/tex]
Therefore
ME=44000/152.15
ME=289.188moles
In conclusion, the number of moles of the enzyme is
ME=289.188moles
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This is the chemical formula for acetic acid (the chemical that gives the sharp taste to vinegar):
CH. CO,H
An analytical chemist has determined by measurements that there are 4.2 moles of carbon in a sample of acetic acid. How many moles of hydrogen are in the
sample?
Be sure your answer has the correct number of significant digits.
Answer:
2.408 moles of hydrogen are in the sample.
Explanation:
Molecular formula of acetic acid =CH3COOH
Ratio of carbon to hydrogen :2/4:1/2
Measured number of moles of carbon atoms = 1.204
Let the moles of hydrogen be = x
Number of carbon atoms in 1.204 mol = 1.204mol*Avogadro number
Number of hydrogen atoms in x mol = x*Avogadro number
As we know that ratio of carbon to hydrogen atoms is 1:2.
1/2=1.204mol* avogadro/ x* avogadro
x = 2.408 moles
2.408 moles of hydrogen are in the sample.
How do you determine the chemical reactivity for nonmetals by using the periodic table?
elements increase in reactivity as they go down in groups and up in periods!!
Number of electrons for all of these even the ones with a number by them ? Will give brain-list!!!!
Explanation:
s=2
p=6
d=10
f=14
I hope this was helpful
Explain what happens to the imidazole side chain of histidine in a buffer of pH 4.0 and at pH 10.2.
Histidine, an essential amino acid, has as a positively charged imidazole functional group. The imidazole makes it a common participant in enzyme catalyzed reactions. The unprotonated imidazole is nucleophilic and can serve as a general base, while the protonated form can serve as a general acid.
What is chemical energy