Answer:
11
∘
C
Explanation:
As far as solving this problem goes, it is very important that you do not forget to account for the phase change underwent by the solid water at
0
∘
C
to liquid at
0
∘
C
.
The heat needed to melt the solid at its melting point will come from the warmer water sample. This means that you have
q
1
+
q
2
=
−
q
3
(
1
)
, where
q
1
- the heat absorbed by the solid at
0
∘
C
q
2
- the heat absorbed by the liquid at
0
∘
C
q
3
- the heat lost by the warmer water sample
The two equations that you will use are
q
=
m
⋅
c
⋅
Δ
T
, where
q
- heat absorbed/lost
m
- the mass of the sample
c
- the specific heat of water, equal to
4.18
J
g
∘
C
Δ
T
- the change in temperature, defined as final temperature minus initial temperature
and
q
=
n
⋅
Δ
H
fus
, where
q
- heat absorbed
n
- the number of moles of water
Δ
H
fus
- the molar heat of fusion of water, equal to
6.01 kJ/mol
Use water's molar mass to find how many moles of water you have in the
100.0-g
sample
100.0
g
⋅
1 mole H
2
O
18.015
g
=
5.551 moles H
2
O
So, how much heat is needed to allow the sample to go from solid at
0
∘
C
to liquid at
0
∘
C
?
q
1
=
5.551
moles
⋅
6.01
kJ
mole
=
33.36 kJ
This means that equation
(
1
)
becomes
33.36 kJ
+
q
2
=
−
q
3
The minus sign for
q
3
is used because heat lost carries a negative sign.
So, if
T
f
is the final temperature of the water, you can say that
33.36 kJ
+
m
sample
⋅
c
⋅
Δ
T
sample
=
−
m
water
⋅
c
⋅
Δ
T
water
More specifically, you have
33.36 kJ
+
100.0
g
⋅
4.18
J
g
∘
C
⋅
(
T
f
−
0
)
∘
C
=
−
650
g
⋅
4.18
J
g
∘
C
⋅
(
T
f
−
25
)
∘
C
33.36 kJ
+
418 J
⋅
(
T
f
−
0
)
=
−
2717 J
⋅
(
T
f
−
25
)
Convert the joules to kilojoules to get
33.36
kJ
+
0.418
kJ
⋅
T
f
=
−
2.717
kJ
⋅
(
T
f
−
25
)
This is equivalent to
0.418
⋅
T
f
+
2.717
⋅
T
f
=
67.925
−
33.36
T
f
=
34.565
0.418
+
2.717
=
11.026
∘
C
Rounded to two sig figs, the number of sig figs you have for the mass of warmer water, the answer will be
T
f
=
11
∘
C
Explanation:
How many moles are 2.60 * 10 ^ 27 atoms of Silicon?
Answer:
~4,317.5 moles of Silicon
Explanation:
Using Avogadro's contant we know that:
1mole = 6.022 x 10^23 atoms
So,to calculate the number of moles in 2.60 x 10^27 atoms of Silicon:
=(2.60 x 10^27 x 1)/(6.022 x 10^23)
~4,317.5 moles of Silicon
Hope it helps:)
How many moles of MgCO3 are present in 252.939 grams of MgCO3?
A. 2
B. 3
C.5
D.6
Answer:
Hello, I was doing this and from my caluclations it should be :
Explanation:
3 Moles.
The three moles of MgCO3 are present in 252.939 grams of MgCO3.
So, option B is correct one .
What is molar mass?The molar mass of substance is equal to mass of one mole of that substance.
Example: Molar mass of MgCO3 is equal to mass of one mole of MgCO3.
Molar mass of Mg = 24.305 u
Molar mass of C = 12.011 u
Molar mass of O = 15.999 u
Molar mass of MgCO3 = Molar mass of Mg + Molar mass of C + Molar mass of O*3
Molar mass of MgCO3 = 24.305 + 12.011 + 15.999 * 3
Molar mass of MgCO3 = 84.3139 gram
Molar mass of MgCO3 contain 84.3139 gram
So, 252.939 grams of MgCO3 = 252.939 grams/84.3139 gram
252.939 grams of MgCO3 = 2.999 moles
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Answer:
H
Explanation:
UMMM H2O .. im assuming the H missing
What are quarks?
A. Particles that bind gluons together within the nucleus
B. Radioactive material that is emitted from a nucleus
C. Subatomic particles that make up protons and neutrons.
D. Fundamental forces acting between two pieces of matter
Answer:
D. Fundamental forces acting between two pieces of matter
Answer:
D. Fundamental forces acting between two pieces of matter
molar absorptivity!
Us Aniline. CH, NH, when reacted with picric acid gives a derivative with a molar ab-
sorptivity of 13 cm E' lat 359 7. What would be the absorbance of a 1.00 x
10" solution or reacico aniline in a 1.00-cm cell? Al 25
Answer:
baba
Explanation:
ndjshddjdjshshshsushs
why the environment in most communities continue to be dirty 2×8
What transition energy corresponds to an absorption line at 460 nm?
A. 6.52 x 10-19 J
B. 4.32 x 10-19 J
C. 4.45 x 10-19 J
D. 2.31 x 10-19 J
Answer:
B. 4.32 x 10-19 J is correct via a p e x
Explanation:
explain the trend in boling point of alcohols in their homologous series
Explanation:
The boiling point of alcohols also increase as the length of hydrocarbon chain increases
The boiling point of alcohols also increase as the length of hydrocarbon chain increases.
Why boiling points of alcohols increases as the length of hydrocarbon chain increasesSince, boiling point depends upon type of bonds present in the molecules.If molecules have hydrogen bonding then boiling point is higher than others because hydrogen bond is stronger bond.So, higher energy or temperature required to break these bond or overcomes the inter molecular force of attraction.Since, alcohol contains hydrogen bonding. So, its boiling points are higher as compare to other compounds.Since, boiling points is also directly proportional to molar mass of molecules. So, molecule have higher molar mass has comparatively high boiling point.Example: An alcohols with lower hydrocarbon chain has lower boiling points as compare to alcohols with higher hydrocarbon chain.To learn more about alcohols,
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What mass of oxygen will react with 2.64 g of magnesium?
2Mg(s) + O2(g) → MgO(s)
Answer:
[tex](24 \times 2) \: g \: of \: magnesium \: reacts \: with \: (16 \times 2) \: g \: of \: oxygen \\ 2.64 \: g \: of \: magnesium \: will \: react \: with \: ( \frac{2.64 \times 16 \times 2}{24 \times 2} ) \: g \\ = 1.76 \: g \: of \: oxygen[/tex]
11. Beh, has no lone pairs of electrons. What's the structure of this molecule?
O A. Tetrahedral
O B. Octahedral
O C. Linear
D. Bent
How much energy is released when 6.0 g of water is condensed from water
vapor?
A. 6.0 g x 1 mol/18.02 g x 4.186 kJ/mol
B. 6.0 g 1 mol/18.02 g 6.03 kJ/mol
O C. 6.0 g x 1 mol/18.02 g * (-285.83 kJ/mol)
O D. 6.0 g x 1 mol/18.02 g x 40.65 kJ/mol
Answer: 6.0g x 1 mol/18.02g x 40,65 kJ/mol which is D
Explanation: Just did
The water vapors change from vapor into water in condensation. The energy released by 6 gm of water is 6.0 g x 1 mol/18.02 g x 40.65 kJ/mol. Thus, option D is correct.
What is the heat of vapourization?The heat of vapourization is the latent heat or enthalpy needed by the liquid to get converted into the vapor or the gaseous phase of the matter. It can be used to determine the energy released or absorbed by the substance.
The heat of vapourization of water is 40.65 kJ/mol, and its molar mass is 18.02 moles.
So, the energy released for the water when it is condensed into vapors will be,
6.0 g x 1 mol/18.02 g x 40.65 kJ/mol
Therefore, the heat of vapourization determines the amount of energy released.
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Using the periodic table as a reference, which pair of elements are nonmetals?
A. oxygen and sulfur
B. cobalt and zinc
C. mercury and lead
D. sodium and iodine
Answer:
A). oxygen and sulphur Non metals are on the right side of the periodic table they are generally in the gaesous form there are as many as 20 non metals in the periodic group ( including halogens and noble gas). non metal are electron withdrawning groups and they generally forms anion they are poor conductors of heat and electricityA gas stp is 4.38 L how many moles are there ?
Answer:
There are 0.195 moles.
Explanation:
1 mol of any gas under STP (meaning 1 atm and 273 K) will occupy 22.4 liters.
With the information above in mind, we can calculate how many moles will occupy 4.38 liters:
4.38 L * 1 mol / 22.4 L = 0.195 molIn 4.38 liters of a gas at STP there will be 0.195 moles.
write 5 acid and 5 akalis
Answer:
5 Acids
Chemical
- Hydrochloric acid in gastric juice
- Sulphuric acid
- Nitric acid
- Uric acid
- Acetic acid
Household
- Vinegar
- Lemon
- Milk
- Batteries
- Soft drinks
5 Alkali
Household
- Dishwashwer soaps
- Detergents
- Toothpaste
- Oven cleaner
- Alkaline batteries
- Sodium bicarbonate
Chemicals
- Sodium hydroxide or lye
- Calcium carbonate (limestone)
- Ammonium hydroxide
- Calcium hydroxide
Concentrated aqueous perchloric acid is 70.5 wt% HClO4 and has a concentration of 11.7 M. Calculate the volume of concentrated perchloric acid that should be diluted to 1.90 L to form a 5.00 M HClO4 solution.
Answer:
0.812 L
Explanation:
As this is a dilution process problem, we can solve it by using the C₁V₁ = C₂V₂ formula, where in this case:
C₁ = 11.7 MV₁ = ?C₂ = 5.00 MV₂ = 1.90 LWe input the data:
11.7 M * V₁ = 5.00 M * 1.90 LAnd solve for V₁:
V₁ = 0.812 LThis means that 0.812 L of concentrated perchloric acid should be diluted to a final volume of 1.90 L.
According to one acid-base theory, water can act as a base because a water molecule can
1) donate an H+ ion
2) accept an H+ ion
3) donate an H- ion
4) accept an H- ion
Answer:
1) donate an H+ ion
Explanation:
option 1 is correct
A single ___ bond is made when two atoms share a pair of ____
Answer:
covalent
valence electrons
Explanation:
The attraction between two atoms that share a pair of valence electrons is known as a covalent bond. The nuclei of both atoms are drawn to the shared electrons. This results in a molecule with two or more atoms. Covalent bonds are formed solely between nonmetal atoms.
Between atoms of the same element or between atoms of different elements, covalent bonds can form. A new substance termed a covalent compound is formed when atoms of various elements create covalent bonds.
1. For the reaction 3A — C, the initial concentration of A was 0.2 M, and the reaction rate was
1.0 M/s. When [A] was doubled, the reaction rate increased to 4.0 M/s. Determine the rate
law for the reaction.
Answer:
[tex]r=25M^{-1}s^{-1}[A]^2[/tex]
Explanation:
Hello there!
In this case, according to the given information for this chemical reaction, it is possible for us to set up the following general rate law and the ratio of the initial and the final (doubled concentration) condition:
[tex]r=k[A]^n\\\\\frac{r_1}{r_2} =\frac{k[A]_1^n}{k[A]_2^n}[/tex]
Next, we plug in the given concentrations of A, 0.2M and 0.4 M, the rates, 1.0 M/s and 4.0 M/s and cancel out the rate constants as they are the same, in order to obtain the following:
[tex]\frac{1.0}{4.0} =\frac{0.2^n}{0.4^n}\\\\0.25=0.5^n\\\\n=\frac{ln(0.25)}{ln(0.5)} \\\\n=2[/tex]
Which means this reaction is second-order with respect to A. Finally, we calculate the rate constant by using n, [A] and r, to obtain:
[tex]k=\frac{r}{[A]^n} =\frac{1.0M/s}{(0.2M)^2}\\\\k=25M^{-1}s^{-1}[/tex]
Thus, the rate law turns out to be:
[tex]r=25M^{-1}s^{-1}[A]^2[/tex]
Regards!
Which waves are blocked by the atmosphere? A. gamma rays B. visible light C. radio waves D. infrared waves
Answer: look at the explanation and try to work it
Explanation: in contrast, our atmosphere blocks most ultraviolet light (UV) and all X-rays and gamma-rays from reaching the surface of Earth. Because of this, astronomers can only study these kinds of light using detectors mounted on weather balloons, in rockets, or in Earth-orbiting satellites.
cloruro de litio mas sodio
Answer:
El cloruro de litio se utiliza para fabricar litio metálico. El cloruro de litio se funde y electroliza. Esto produce litio metálico líquido.
Explanation:
sowwy si mi español es malo
Answer:
give him brainliest
Explanation:
A sample of aluminum absorbed 9.86 J of heat and its temperature increased from 23.2 and 30.5 degrees * C . What is the mass of the aluminum? Th specific heat of aluminum is 0.902 J/g^ C . Round your answer to 2 significant figures. Do not include units in your answer. *
Explanation:
H=mc×∆©
9.86=m×0.902×(30.5-23.2)
m=1.5
Explanation:
The specific heat of a substance is the amount of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius. The formula for calculating the heat absorbed or released by a substance is `q = mcΔT`, where `q` is the heat absorbed or released, `m` is the mass of the substance, `c` is the specific heat of the substance, and `ΔT` is the change in temperature.
In this case, we can use this formula to solve for the mass of the aluminum sample. We know that `q = 9.86 J`, `c = 0.902 J/g°C`, and `ΔT = 30.5°C - 23.2°C = 7.3°C`. Plugging these values into the formula, we get:
`9.86 J = m * 0.902 J/g°C * 7.3°C`
Solving for `m`, we find that the mass of the aluminum sample is approximately `1.5 g`, rounded to 2 significant figures.
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What mass of HF is produced according to the given equation when 2.397 grams of each reactants are combined?
CaF2 + H2SO4 --> CaSO4 + 2HF
+HF is the answer
Explanation:
The compound aluminum nitride () is a compound semiconductor having mixed ionic and covalent bonding. The electronegativities for and are 1.5 and 3.0 respectively. Calculate the fraction of the bonding that is ionic.
Answer:
Fraction ionic = 0.43
Explanation:
To solve this question, we must, as first, find the fraction of the bond that is covalent using the equation:
Fraction Covalent = exp (-0.25*(Enitride - EAl)²)
Fraction covalent = exp (-0.25*(3.0- 1.5)²)
Fraction covalent = exp (-0.25*2.25)
Fraction covalent = exp (-0.5625)
Fraction covalent = 0.57
As:
1 = Fraction Covalent + Fraction Ionic:
Fraction ionic = 1 - 0.57
Fraction ionic = 0.43
If 1.00 mol of an ideal monatomic gas initially at 74 K absorbs 100 J of thermal energy, what is the final temperature
Answer:
T = 82 K
Explanation:
The computation of the final temperature is shown below;
Given that
T_0 denotes the initial temperature of the gas i.e. 74 K
T denotes the final temperature of the gas = ?
n denotes number of moles of monoatomic gas i.e. 1.00 mol
R denotes universal gas constant = 8.314
c denotes the heat capacity at constant volume i.e.
= (1.5) R = (1.5) (8.314)
= 12.5
Q denotes the Amount of heat absorbed i.e 100 J
We know that
Amount of heat absorbed is provided as
Q = n c (T - T_0)
100 = (1) (12.5) (T - 74)
T = 82 K
An electron in a hydrogen atom moves from level 1 to level 4. The electron then drops from level 4 to level 2. Which
statement describes the most likely result?
The energy absorbed in the first move equals the energy released in the second move.
The energy absorbed in the first move is greater than the energy released in the second move.
O The energy released in the first move equals the energy absorbed in the second move.
The energy released in the first move is greater than the energy absorbed in the second move.
Answer:
Your answer would be B because In the first move energy was absorbed, because when energy is gained an electron moves to a higher energy level in the second move energy will be released because that is how an atom moves to a lower energy level. The jump from level 1 to 4 was bigger than the drop from 4 to 2, because in the first move it moved from more orbitals. thus describing the the energy in the first move had a far energy released in the second move.
问题2
15
The reaction causes the temperature of its surroundings to decrease is
therefore heat is
by the reaction.
and
Select the two words that best complete this sentence.
a. endothermic, absorbed
b. exothermic, released
c. exothermic, absorbed
d. endothermic, released
Answer:
a endothermic, absorbed
how many moles of potassium+hydroxide+would+react+with+one+mole+of+hydrocloric acid
Answer:
1 mole of potassium hydroxide, KOH
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
KOH + HCl —> KCl + H₂O
Considering the balanced equation above, we can see clearly that 1 mole of potassium hydroxide, KOH reacted with 1 mole of hydrochloric acid, HCl.
Therefore, we can conclude that at every given point, 1 mole of potassium hydroxide, KOH is required to react with 1 mole of hydrochloric acid, HCl.
The specific heat of palladium is 0.239 J/g°C. How much heat (q) is released when a 10.0 g piece of platinum cools from 100.0°C to 50.0°C?
Answer:
119.5 J
Explanation:
First we calculate the temperature difference:
ΔT = 100 °C - 50 °C = 50 °CThen we can calculate the heat released by using the following formula:
q = Cp * ΔT * mWhere q is the heat, Cp is the specific heat, ΔT is the temperature difference and m is the mass.
We input the data:
q = 0.239 J/g°C * 50 °C * 10.0 gq = 119.5 JWhat is the [OH-] in a solution if the [H*] = 1.2 x 10-3 M?
We know that [OH⁻] * [H⁺] = 10⁻¹⁴
plugging the value of [H⁺]
[OH⁻] * 1.2 * 10⁻³ = 10⁻¹⁴
[OH⁻] = 10⁻¹⁴ * (10³/1.2)
[OH⁻] = 833.3 * 10⁻¹⁴
[OH⁻] = 8.33 * 10⁻¹²
A yellow powder and a blue liquid are shaken together in a test tube to produce a clear green mixture that is all liquid.
Which of the following best describes the behavior of the above pair of substances?
Answer:
hkj
Explanation: