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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What is the purpose of attaching the clip clamp with the graphite of the pencil to the battery
What is the pH of the solution obtained by mixing 68.00 mL of 0.280 M HCl and 60.00 mL of 0.125 M NaOH
The pH of the solution is approximately : 1.05
Given data :
volume of HCl = 68.00 mL = 0.068 L
concentration of HCl = 0.280 M
Volume of NaOH = 60 mL = 0.6 L
concentration of NaOH = 0.125 M
Determine the pH of the solutionFirst step : determine the number of mol of HCl and NaOH
mol of HCl = 0.068 * 0.280 = 0.0190 mol HCl
mol of NaOH = 0.06 * 0.125 = 0.0075 mol NaOH volume of
excess moles of H⁺ after reaction = 0.0190 - 0.0075 = 0.0115 mol
Next step : determine the pH value of the solution
Total volume of solution = 0.068 + 0.060 = 0.128
concentration of the solution [ H⁺ ] = excess moles / total volume
= 0.0115 / 0.128 = 0.0898
Therefore
pH = - log [ H⁺ ]
= - log ( 0.0898 ) = 1.047 ≈ 1.05
Hence we can conclude that The pH of the solution is approximately : 1.05 .
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HBr + Al(OH)3 = H2O + AlBr3, how do I balance this equation?
Answer: This is an acid-base reaction (neutralization): Al(OH) 3 is a base, HBr is an acid. ; Colorless gas with a sharp, irritating odor.
...
Search by products (AlBr 3, H 2O)
1 HBr + Al(OH)3 → H2O + AlBr3
2 Al2O3 + HBr → H2O + AlBr3
Explanation:
Two cities in Germany are located 25 km apart. What is the
distance in miles?
Answer:
15.5343
Explanation:
if Tim and maliyah went to the moon and the moon is smaller than earth both maliyah and Tim's mass would stay the same and their weight would change
Answer:
no
Explanation:
Weight is a measure of how much gravity pulls on a mass or object. On the moon, there is less gravity pulling on objects, so they weigh less. ... But does its mass changejust because it is on the moon? No, it is still the same size and looks the same, it just has less gravity pulling on it, so it weighs less.
what do columns on the periodic table tell us?
Answer:
Column on the periodic table tell the number of valence electrons and the types of chemicals, such as metals, nonmetals, alkaline earth metals, metalloids, halogens, noble gases.
Explanation:
The periodic table is an arrangement of the elements in order of their atomic numbers so that elements with similar properties appear in the same vertical column or group.
Please help! How many orbits will the Bohr models in the fourth period have?
Answer:
32 electron
Thus,the fourth level can hold up to 32 electrons,2 in the s orbital,6 in the three p orbitals,10 in the five d orbitals,and 14 in the seven f orbitals.
how many grams of water are needed to react with 71.0g CaN2?
Answer:
1
Explanation:
Mass of
C
a
C
N
2
= 75.0 g
From the equation,
C
a
C
N
2
(
s
)
+
3
H
2
O
(
l
)
→
C
a
C
O
3
(
s
)
+
2
N
H
3
(
g
)
1 mol of
C
a
C
N
2
reacts with 3 moles of water to give calcium carbonate and ammonia.
Number of moles of
C
a
C
N
2
,
n
=
G
i
v
e
n
m
a
s
s
M
o
l
a
r
m
a
s
s
Molar mass of
C
a
C
N
2
= 92.11 g/mol
Therefore,
n
C
a
C
N
2
=
75
g
92
.11
g
/
m
o
l
=
0
.814
m
o
l
Moles of water =Therefore,
n
C
a
C
N
2
=
75
g
92
.11
g
/
m
o
l
=
0
.814
m
o
l
Moles of water =
3
×
0
.814
m
o
l
e
s
=
2
.442
m
o
l
e
s
Mass of water needed;
=
m
o
l
e
s
o
f
w
a
t
e
r
×
m
o
l
a
r
m
a
s
s
o
f
w
a
t
e
r
=
2
.442
m
o
l
×
18
g
/
m
o
l
=
43
.956
g
Thus, 43.96 g of water is needed to react with 75 g of
C
a
C
N
2
.
What is a type of nuclear reaction in which the nucleus of a heavy atom splits into two or more smaller nuclei that have masses of relatively similar size?
A: gamma radiation
B: nuclear fusion
C: chain reaction
D: nuclear fission
The table below gives the numbers of protons, electrons, and neutrons in four atoms.
Atom
Number of protons
Number of neutrons
Number of electrons
1
9
8
9
2
19
9
18
3
9
9
10
9
10
19
Based on the table, which atom has a charge of -1?
1
2
Оооо
3
4
Answer:
C. Atom 3
Explanation:
I'm sorry if I answered this late, but hope this helps! :D
Answer:
c
Explanation:
edge 2021
the enzyme urea catalyses this reaction. If urea is added to a solution that contains ammonia and other nitrogen- containing compounds (but no urea), will the urea catalyse any reactions? Explain your answer?
Answer:
The enzyme urease catalyzes the hydrolysis of urea into ammonia and carbon dioxide. If urease is added to any compound which has no urea, it will not catalyze any reaction because if there is no urea, urease will not bind to any substance.
If the temperature is below zero, what will the precipitation most likely be?
A(hail, B(rain, C(snow, D(sleet.
Answer: C Snow
Explanation:
Because the temperature is low and it is below freezing temperature. Sorry if I am wrong.
3. Nitrogen contains two naturally occurring isotopes, N-14 with a mass of 14.003 amu and N-15 with a mass of 15.000 amu. What are the percentages of the two isotopes in naturally occurring nitrogen?
Answer:
Explanation:
fe-45 and O-15 im sure :)
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Pure copper may be produced by the reaction of copper (I) sulfide with oxygen gas:
Cu2S (s) + O2 (g) --> 2Cu (s) + SO2 (g)
If 3-kg of copper (I) sulfide reacts with excess oxygen, what mass of copper metal may be produced??
If 3-kg of copper (I) sulfide reacts with excess oxygen, 3.9 kg of copper metal may be produced.
Let's consider the following balanced equation for the obtaining of pure copper.
Cu₂S(s) + O₂(g) ⇒ 2 Cu(s) + SO₂(g)
The molar mass of Cu₂S is 95.61 g/mol. The moles corresponding to 3 kg (3000 g) of Cu₂S are:
[tex]3000 g \times \frac{1mol}{95.61g} = 31 mol[/tex]
The molar ratio of Cu₂S to Cu is 1:2. The moles of Cu obtained from 31 moles of Cu₂S are:
[tex]31 mol Cu_2S \times \frac{2molCu}{1molCu_2S} =62 mol Cu[/tex]
The molar mass of Cu is 63.55 g/mol. The mass corresponding to 62 moles of Cu is:
[tex]62 mol \times \frac{63.55g}{mol} = 3.9 \times 10^{3} g = 3.9 kg[/tex]
If 3-kg of copper (I) sulfide reacts with excess oxygen, 3.9 kg of copper metal may be produced.
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What is the name of the cycle in which decomposes break down animal waste
A. Water cycle
B. Nitrogen cycle
C. Carbon dioxide-oxygen cycle
D. Rick cycle
Answer:
C. Carbon Dioxide-oxygen Cycle
Explanation:
Bacteria plays an important role in carbon cycle. Bacteria are decomposers that break down organic compounds. They decomposes plant and animal waste products and return carbon back in the environment.
Hope it helps:)))
Which process is a chemical change?
burning a match
boiling water
melting ice
breaking glass
Answer:
Burning a match... i'm pretty sure.
Explanation:
All the other are phisical changes while Fire is a chemical reaction.
Answer:
Burning a match is a chemical change.
Explanation:
Burning is defined as the rapid oxidation of a combustible material.
Complete oxidation of the match stick results in an entirely different compound (the ash) while electrons are lost by the wood of the match.
What is kinetic energy?
A: energy that depends on an object’s motion
B: energy that exists in the form of heat
C: stored energy that depends on an object’s chemical composition
D: stored energy that depends on an object’s position
Answer:
the answer should be A. energy that depends on an object's motion
Answer: A
Explanation: Kinetic energy is energy of build up of motion .
A sample of boron consist of 10B (mass 10.0 amu) and 11B(mass 11.0). If the average atomic mass of B is 10.8 amu, what is the % abundance of each boron isotope
Answer:
%abundance of isotope B-11 is 80%, therefore, the %abundance of isotope B-10 is 20%.
Explanation:
The average atomic mass of an element is actually a weighted average atomic mass, taking into account the percent abundance of the naturally occurring isotopes of the element.
To calculate the weighted average mass, you must take the sum of atomic masses of all the naturally occurring isotopes multiplied by their %abundance.
Ave At. Mass = sum of [(isotopic mass)(%abundance)]/100
If we let the %abundance of B-11 be represented by X, then the %abundance of B-10 must be (100-X).
Now we can set up the following equation and solve for X
10.8 = [(10)(100-X) + (11)(X)]/100
1080 = 1000 - 10X + 11X
80 = X
So, the %abundance of isotope B-11 is 80%, therefore, the %abundance of isotope B-10 is 20%.
Which statement best describes a physical change?
O Changes can occur to certain chemical properties of the substance, but the overall shape of the substance will
remain the same.
Changes can occur to certain physical properties of the substance, but the overall shape of the substance will
remain the same.
O Changes can occur to physical properties of a substance, but the chemical composition of the substance remains
the same.
O Changes can occur to chemical properties of a substance, but the chemical composition of the substance remains
the same.
Answer:
Changes can occur to physical properties of a substance, but the chemical composition of the substance remains
define conductor and insulator ?
Answer:
A conductor is an object or material that conducts heat, electricity, or sound. Examples of metals such as aluminum, steel, iron, and others. Meanwhile, insulators are objects that are difficult to conduct heat, such as ebonite, plastic, cloth, and others
Conductor is something which conducts electricity
examples are copper and other metals
Insulators are quite the opposite, they do not let electricity pass by them, examples are plastics, rubber and wood
Which element has four times as many protons in its nucleus than are found in Neon?
A.Si
B.Ca
C.Zr
D. Hg
Answer: Zr or Zirconium
Explanation: Neon has 10 Protons and four times ten is 40. And Zirconium has 40 protons the symbol for Zirconium is Zr
Neon has 10 protons, the element which has four times more protons than Neon in its nucleus is Zirconium(Zr).
What is a proton?Every atom has a proton, a subatomic particle, in its nucleus. The particle possesses an electrical charge that is positive and opposite to the electrons. A single proton has a mass of only [tex]1.673[/tex]×[tex]10^{-27}[/tex] kilogram when isolated. Just slightly less than a neutron's mass.The atomic number is the number of protons in an element's nucleus. Each element is given a unique identification by this number. The number of protons in the nucleus is constant in all atoms of a given element. The nucleus of an atom of pure hydrogen is made up entirely of one proton. All other elements' nuclei almost usually have neutrons in addition to protons.Protons need not just be found in atoms' nuclei. Protons acquire fascinating, peculiar, and potentially hazardous characteristics when they are discovered outside of atomic nuclei, which are analogous to neutrons in comparable situations. Protons have another characteristic, they can be accelerated by electric and/or magnetic fields because they carry an electric charge. During solar flares, a lot of high-speed protons and atomic nuclei holding them are released. The acceleration of the particles by the earth's magnetic field results in geomagnetic storms, which are ionospheric disturbances.To learn more about Proton, refer to https://brainly.com/question/1805828
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Arrange the following ions in order of increasing ionic radius: nitride ion, magnesium ion, fluoride ion, aluminum ion.
Explanation:
Nitride ion > Fluoride ion > Magnesium ion > Aluminum ion
what is the maximum gauge pressure of waters that can measured using piezometer tube 2m high?
Answer:
P = ρgh = 1000 × 9.81×2 =19.62 kN/m^2
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If 3.49 g of silver chloride, AgCl, is produced from the reaction of 5.95 g AgNO3 with excess BaCl2,
what is the percentage yield ?
(molar masses: AgCl = 143.4 g/mol, AgNO3 = 169.9 g/mol)
2 AgNO3(aq) + BaCl2(aq) + 2 AgCl(s) + Ba(NO3)2(aq)
Answer:
that not of i grade sorry
Explanation:
What happens to the temperature of water as it is boiling? Increase, decrease, or remains the same?
Answer:
Increased
Explanation:
Write a balanced equation for each of the following decomposition reactions:
Solid stannous chlorate decomposes with heat to give stannous chloride and oxygen gas.
Sn(ClO3)2 -> SnCl2 + 3O2
Explanation: There should be equal amounts of each element on both sides. This assumes it’s referring to Sn 2+, and not Sn 4+.
The balanced chemical equation will be:
[tex]\rm \bold{(SnClO_3)_2\;\overset{\Delta}{\rightarrow}\;SnCl_2\;+\;3\;O_2}[/tex]
Stannous chlorate has been also known as Tin chlorate. The compound has been a white crystalline powder and has been used for the sensitization of the metal.
The decomposition of Stannous chlorate under the influence of heat has resulted in the formation of stannous chloride and oxygen gas.
The reaction can be given as:
[tex]\rm (SnClO_3)_2\;\overset{\Delta}{\rightarrow}\;SnCl_2\;+\;O_2[/tex]
The number of atoms on the reactant and the product side is not equal. By putting the coefficient to the compound, the reaction can be balanced. The balanced chemical equation will be:
[tex]\rm \bold{(SnClO_3)_2\;\overset{\Delta}{\rightarrow}\;SnCl_2\;+\;3\;O_2}[/tex]
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5. Chemistry helps firefighters
A. determine which chemicals to use to fight different types of fires
B. identify the temperatures at which different substances burn
C. know the angles at which they can safely deploy ladders
D. calculate how much water pressure is available at a hydrant
Answer:
A
Explanation:
determine which chemicals to use to fight different types of fires
the only one that relates to chem
Which representative element has the largest atomic radius ?
Answer:
francium
Explanation:
the atomic radius increases from top to bottom in a group, and decreases from left to right across a period.
2. I take and absorb the nutrients that your body needs from your
food and I put it in your bloodstream so your body can use it.
What am l?
Answer:
The small intestine
Explanation:
You are the small intestine
500mg of iron(ll) complex ferrous bisglycinate hydrochloride was dissolved in dilute H2SO4 and titrated with 0.0200 mol. dm3 KMnO4 18.10cm3 of KMnO4 solution were require to reach the end point the equation for the titration reaction is as follows 5Fe2+ + MnO4- + 8H+ - - > 5Fe2+ + Mn2+ +4H2O
Calculate the
1.number of moles of Fe2+ in the capsule
2.mass of iron in the capsul
3.molar mass of the iron (ll) complex assuming 1mole of the complex contains 1mole of iron. (Fe=55.9gmol-1)
Using the stoichiometry of the reaction, we can obtain the molar mass of the complex as 276 g/mol. The number of moles iron II as 0.00181 moles and the mass of iron II as 0.1 g.
Redox reactionA redox reaction is one in which there is loss or gain of electrons. The equation of the reaction is 5Fe2+ + MnO4- + 8H+ - - > 5Fe2+ + Mn2+ +4H2O
Number of moles of permanganate = 0.0200 mol. dm3 * 18.10cm3/1000 L
= 0.000362 moles
If 5 moles of iron II reacted with 1 mole of permanganate
x moles of iron II reacts with 0.000362 moles of permanganate
x = 5 moles * 0.000362 moles/ 1 mole
= 0.00181 moles of iron II
Recall that;
Number of moles = mass/molar mass
Molar mass of iron II = 56 g/mol
0.00181 moles = x/56 g/mol
x = 0.00181 moles * 56 g/mol = 0.1 g
If 1 mole of the complex contains 1 mole of iron then;
0.00181 moles = 500 * 10^-3/MM
MM= 500 * 10^-3/0.00181 moles
MM = 276 g/mol
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