Answer:
Here's what I got.
Explanation:
Interestingly enough, I'm not getting
0.0341% w/v
either. Here's why.
Start by calculating the percent composition of chlorine,
Cl
, in calcium chloride, This will help you calculate the mass of chloride anions,
Cl
−
, present in your sample.
To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that
1
mole of calcium chloride contains
2
moles of chlorine atoms.
2
×
35.453
g mol
−
1
110.98
g mol
−
1
⋅
100
%
=
63.89% Cl
This means that for every
100 g
of calcium chloride, you get
63.89 g
of chlorine.
As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every
100 g
of calcium chloride, you get
63.89 g
of chloride anions,
Cl
−
.
This implies that your sample contains
0.543
g CaCl
2
⋅
63.89 g Cl
−
100
g CaCl
2
=
0.3469 g Cl
−
Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in
100 mL
of this solution.
Since you know that
500 mL
of solution contain
0.3469 g
of chloride anions, you can say that
100 mL
of solution will contain
100
mL solution
⋅
0.3469 g Cl
−
500
mL solution
=
0.06938 g Cl
−
Therefore, you can say that the mass by volume percent concentration of chloride anions will be
% m/v = 0.069% Cl
−
−−−−−−−−−−−−−−−−−−−
I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.
.
ALTERNATIVE APPROACH
Alternatively, you can start by calculating the number of moles of calcium chloride present in your sample
0.543
g
⋅
1 mole CaCl
2
110.98
g
=
0.004893 moles CaCl
2
To find the molarity of this solution, calculate the number of moles of calcium chloride present in
1 L
=
10
3
mL
of solution by using the fact that you have
0.004893
moles present in
500 mL
of solution.
10
3
mL solution
⋅
0.004893 moles CaCl
2
500
mL solution
=
0.009786 moles CaCl
2
You can thus say your solution has
[
CaCl
2
]
=
0.009786 mol L
−
1
Since every mole of calcium chloride delivers
2
moles of chloride anions to the solution, you can say that you have
[
Cl
−
]
=
2
⋅
0.009786 mol L
−
1
[
Cl
−
]
=
0.01957 mol L
−
This implies that
100 mL
of this solution will contain
100
mL solution
⋅
0.01957 moles Cl
−
10
3
mL solution
=
0.001957 moles Cl
−
Finally, to convert this to grams, use the molar mass of elemental chlorine
0.001957
moles Cl
−
⋅
35.453 g
1
mole Cl
−
=
0.06938 g Cl
−
Once again, you have
% m/v = 0.069% Cl
−
−−−−−−−−−−−−−−−−−−−
In reference to the explanation you provided, you have
0.341 g L
−
1
=
0.0341 g/100 mL
=
0.0341% m/v
because you have
1 L
=
10
3
mL
.
However, this solution does not contain
0.341 g
of chloride anions in
1 L
. Using
[
Cl
−
]
=
0.01957 mol L
−
1
you have
n
=
c
⋅
V
so
n
=
0.01957 mol
⋅
10
−
3
mL
−
1
⋅
500
mL
n
=
0.009785 moles
This is how many moles of chloride anions you have in
500 mL
of solution. Consequently,
100 mL
of solution will contain
100
mL solution
⋅
0.009785 moles Cl
−
500
mL solution
=
0.001957 moles Cl
−
So once again, you have
0.06938 g
of chloride anions in
100 mL
of solution, the equivalent of
0.069% m/v
.
Explanation:
i think this is it
what is the formula of acceleration?
Answer:
The formula of acceleration is final velocity-initial velocity÷time taken
Explanation:
v-u/t
Answer:
acceleration = (vFinal − vInitial)/ (tFinal − tInitial) Where v stands for velocity and t stands for time.
Angela does 50 Joules of work to lift her 2.5 kg grocery bag. How far (distance) did she lift the grocery bags?
Which reaction demonstrates bonds breaking?
PC13(g) → P (g) + 3Cl (g)
P(g) + 3 Cl(g)
PC13 (g)
When the temperature of the water was 10°C the waterweed did not produce bubbles.
Suzi increased the temperature of the water in the water-bath to 20°C. The waterweed started to produce bubbles.
She waited two minutes before starting to count the bubbles.
Explain why she waited for two minutes before she started to count the bubbles.
Science
Explanation:
she could waited for the saturated vapour pressure to equal the prevailing atmospheric pressure
ergo boiling to take place seeing as she had gotten the first indication that boiling had started
1. For the reaction below, which change would cause the equilibrium
to shift to the right?
CH,(g) + 2H,S(g) + heat --
CS,(g) + 4H,(g)
(a) Decrease the concentration of H,S.
(b) Increase the pressure on the system.
(c) Increase the temperature of the system.
(d) Increase the concentration of CS,
(e) Decrease the concentration of CH.
option c is the correct answer
because the gas there will be evolved and caused the equilibrium to shift to right side
Prokaryotic and eukaryotic cells have many different characteristics. One difference
between prokaryotic and eukaryotic cells is that all eukaryotic cells —
Answer:
Have a nucleus
Explanation:
Pls check..
A gas diffuses 1/6 times faster than hydrogen gas (H2).
What is the molar mass of the gas? (5 points)
a
59.95 g/mol
b
66.54 g/mol
c
68.68 g/mol
d
72.58 g/mol
Answer:
72.58 g/mol
Explanation:
mark me brainless if I am ✅
The relationship between the rate of diffusion and the molar mass is given by Graham's law. A gas diffusing 1/6 times faster than hydrogen will have a molar mass of 72.58 g/mol. Thus, option d is correct.
What is Graham's law?Graham's law states the inverse relationship between the rate of diffusion and the square root of the molar mass of the gas. It is given as,
Rate = 1 ÷ √M
The molar mass of the gas that diffuses 1/6 times faster than hydrogen is calculated as,
R₁ ÷ R₂ = √ (M₂ ÷ M₁)
Here,
The molar mass of hydrogen = M₁
The molar mass of unknown gas = M₂
Rate of diffusion of hydrogen gas = R₁
Rate of diffusion of unknown gas = R₂ = 1 / 6 R₁
Substituting values:
R₁ ÷ 1/6 R₁ = √M₂ ÷ 2
6 × 1.414
= 8.485
= 84.85 g/mol ≈ 72.58 g/mol
Therefore, option d. 72.58 g/mol is the molar mass of unkown gas.
Learn more about Graham's law here:
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A gas has a volume of 300 mL in a rigid container at 50oC and 1.75 atm. What will be its pressure at 100K?
Answer:
Its pressure will be 0.54 atm at 100 K.
Explanation:
Gay-Lussac's law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of collisions with the walls increases, that is, the pressure increases. That is, the pressure of the gas is directly proportional to its temperature.
Gay-Lussac's law can be expressed mathematically as the quotient between pressure and temperature equal to a constant:
[tex]\frac{P}{T} =k[/tex]
Studying two different states, an initial state 1 and a final state 2, it is satisfied:
[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]
In this case:
P1= 1.75 atmT1= 50 °C= 323 K (being 0 C=273 K)P2= ?T2= 100 KReplacing:
[tex]\frac{1.75 atm}{323 K} =\frac{P2}{100 K}[/tex]
Solving:
[tex]P2= 100 k*\frac{1.75 atm}{323 K}[/tex]
P2= 0.54 atm
Its pressure will be 0.54 atm at 100 K.
You can prepare a buffer solution by combining equal moles of which pair of substances?
A. weak acid and its conjugate base
B. strong acid and a strong base
C. strong base and its conjugate acid
D. salt and a weak acid
Answer:
A. weak acid and its conjugate base
Explanation:
A buffer solution can be made with a weak acid and conjugate base or a weak base and conjugate acid.
This may help you:
https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Acids_and_Bases/Buffers/Introduction_to_Buffers
What is the pressure of gas at 496 Liters and 200 Kelvin if the original pressure was 0.250 atm. at 300 liters and 400 kelvin?
Answer:
0.076 atm
Explanation:
Using the combined gas law formula;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
T1 = initial temperature (K)
T2 = final temperature (K)
V1 = initial volume (L)
V2 = final volume (L)
According to the information provided in this question;
P2 = ?
P1 = 0.250 atm
V2 = 496 L
V1 = 300 L
T2 = 200K
T1 = 400K
Using P1V1/T1 = P2V2/T2
0.250 × 300/400 = P2 × 496/200
75/400 = 496 P2/200
0.1875 = 2.48P2
P2 = 0.1875 ÷ 2.48
P2 = 0.076 atm
Balance the chemical equation using the drop-down options.
CaC2 +
A H20 --->
Ca(OH)2
A C2H2 +
Answer:
CaC2 + 2H20 ⇋Ca(OH)2 + C2H2
Explanation:
CaC2 + A H20 ---> Ca(OH)2 + A C2H2
This is calcium carbide reacting with water to produce calcium hydroxide and ethyne commonly called acetylene.
Let's now balance the equation.
CaC2 + 2H20 ⇋Ca(OH)2 + C2H2
A big ______ shows up on a weather map as really close/tight isobars & in weather as fast, strong winds
dewpoint
air pressure gradient
precipitation
barometer
Answer:
A BIG DI*CK
Explanation:
What volume in milliliters of 6.0 M NaOH is needed to prepare 175mL of 0.20 M NaOH by dilution?
Answer:
V¹N²= V²N²
here V¹= ?
N¹= 6.00
V²= 175ml
M²= 0.2M
So V¹= (V²N²)/N² = (175 x 0.2)/6
V¹ = 5.83 ml
Explanation:
Therefore diluting 5.83 ml of 6.00M NaOH to 175 m l ,we get 0.2M Solution.
5.83 ml of 6.0 M NaOH is required to prepare 175 ml of 0.20 M NaOH by dilution according to the concept of molar concentration.
What is molar concentration?
Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.For the mentioned example volume of 6 M NaOH is found out as,
M₁V₁=M₂V₂
∴V₁=0.20×175/6=5.83 ml
Thus, 5.83 ml of 6 M NaOH is required to prepare 175 ml of 0.20 M NaOH by dilution.
Learn more about molar concentration,here:
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Which number represents an acidic pH, 3 or 12
Answer:
Explanation:
The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.
Answer:
pH 3
Explanation:
The lower the pH the more acidic. The higher is more bleachier.
If 5.85 moles of CaCO3 are used in an experiment, how many moles of carbon dioxide are created? (Be sure to include units in your answer.) CaCO3 → CaO + CO2
Answer:
5.85 moles of carbon dioxide are created.
Explanation:
The balanced reaction is:
CaCO₃ → CaO + CO₂
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
CaCO₃: 1 mole CaO: 1 moleCO₂: 1 moleThen you can apply the following rule of three: if by stoichiometry 1 mole of CaCO₃ produces 1 mole of CO₂, 5.85 moles of CaCO₃ will produce how many moles of CO₂?
[tex]moles of CO_{2}=\frac{5.85 moles of CaCO_{3} *1mole of CO_{2} }{1 mole of CaCO_{3}}[/tex]
moles of CO₂= 5.85
5.85 moles of carbon dioxide are created.
Which factor will INCREASE the rate of solvation of a solid in a liquid?
A. decreasing the surface area of the solute
B. decreasing the temperature
C. allowing the mixture to sit undisturbed
D. increasing the temperature
(It’s D)
Answer:
the answer is D =decreasing the temperature ️️️
A titration is completed using 10.0 mL of 0.50 M HCl and an unknown concentration of NaOH solution. If the equivalence point is reached when exactly 20.0 mL of the NaOH solution is added, what must the concentration of the NaOH solution be?
Answer:
0.172 M
Explanation:
can someone help me with these pls
Answer:
C is the correct answer
Explanation:
as temperature increases the pressure also increases
If two half lives have passed since a scientist collected a 1.00- gram sample of a U-235, how much U-235 is left now?
answers for most finals chem test questions (10th)
Answer:
one quarter of the original amount, so 0.25 g
Explanation:
Answer:
C
Explanation:
i need help with this asap.
Answer:
H30+ First H20 Second N03 Third HNO3 Fourth
Explanation:
Please help me ASAP!!!!
Answer:
Explanation:
Determine the balanced chemical equation for the chemical reaction.
Convert all given information into moles (most likely, through the use of molar mass as a conversion factor).
Calculate the mole ratio from the given information.
If , 1000 mL = 1L , what is 4.26L into mL?
Answer:
4260ml
Explanation:
Determine the molecular formula of the following: Molar
mass of compound equals 78.11 g/mol and an empirical
formula of CH.
NEED HELP!!
Answer:
C6H6
Explanation:
The molecular formula of a substance can be determined by using the expression:
(CH)n = 78.11g/mol
Where;
C = 12, H = 1
(12 + 1)n = 78.11
13n = 78.11
n = 78.11 ÷ 13
n = 6.008
n = 6
Hence, the molecular formula is as follows:
(CH)6
Molecular formula = C6H6
a toy car is place at the top of a ramp and released which situation describes how car energy is transformed
I don’t see a list of differing situations, but I can explain what happens:
Edit (to be more specific):
When you release a toy car on a ramp; the potential energy is at its highest point (with little kinetic energy). As the car accelerates downwards, kinetic energy increases. At the bottom of the ramp, there is minimum potential energy, though maximum kinetic energy.
How many atoms are in one mole of barium ?
Answer:
3 atoms
Explanation:
"In one mole of Barium, there are 3 x [tex]N_{A}[/tex] barium and chlorine atoms, where [tex]N_{A}[/tex] is Avagadro's Number, 6.022 x [tex]10^{23}[/tex] " - anor277 via Socratic
A Chemist reacted magnesium and aluminum oxide. A reaction takes place. Explain why
Explanation:
when Magnesium is reacted with Aluminum oxide, Aluminum being a less reactive metal than magnesium, is replaced by magnesium
Al2O3 + 3Mg - 3MgO + 2Al
hence reaction takes place
El modelo atómico postulado por Shrodinger refiere la corteza atómica como una nube electrónica. Verdadero. Falso.
Answer:
Falso.
Explanation:
El modelo cuántico (no relativista) de Schrodinger, piensa a los electrones como ondas estacionarias, tal que la amplitud de dichas ondas decae muy rápidamente cuando se "alejaban" del radio atómico. (Es decir, habia poca probabilidad de que los electrones escaparan del radio atomico, y era por ello que se quedaban orbitando cerca del nucleo). Es decir, podríamos pensar en esto como una "nube de probabilidades" más que una nube electronica
La idea de nube electrónica realmente viene de modelos previos, como el de Rutherford o el de Bhor, los cuales eran modelos clásicos.
Answer the following questions when 45mL sample of 0.175 M KOH is titrated with 0.200 M HI
Find the initial pH of the 0.175 M KOH solution.
Find the pH when 18 mL of 0.200 M HI have been added.
Find the pH when 63 mL of the 0.200 M HI have been added.
How many milliliters of 0.200 M HI must be added to reach the equivalence point?
What is the pH at the equivalence point?
Answer: Initial pH is 13.243
12.83
1.3
40ml
7
Explanation:
Just finished the test.
Which of the following isotopes have 8 neutrons in the nucleus?
O-15
O-17
C-13
C-14
Answer:
C-14 have 8 neutrons in the nucleus.
Carbon atoms with 8 neutrons have an atomic mass of 14 (6 protons + 8 neutrons = 14), so this isotope of carbon is named carbon-14.
hope it helps :)
Explanation:
Answer:
its d
Explanation:
edge 21
PLEASE HELP NEED ANSWER ASAP!!!!
Use 3 H2(g) + N2(g) <--> 2 NH3 (g) + 92.4 kJ
At equilibrium, if the hydrogen (H2) concentration is increased, the ammonia(NH3) concentration will
Select one:
a. decrease
b. shifts back and forth
c. increase
d. remain the same
Answer:
the correct answer is option A. decrease