What is the pH of an aqueous solution that has a hydroxide ion concentration of 1.0 x 10^-5 M?
Answer:
pH = 9
Explanation:
pOH = -log[OH-] = -log(1.0 x10^-5) = 5
pOH + pH = 14
pH = 14 - 5 = 9
what is the mass of [tex]Fe^{2+}[/tex] in 5 tablets of iron if the number of moles of [tex]Fe^{2+}[/tex] is 4.2225 x [tex]10^{-4}[/tex] mol.
[ Ar = Fe, 56 ]
Answer:
Approximately [tex]0.11823\; \rm g[/tex] in total for the five tablets.
(Approximately [tex]2.3646 \times 10^{-2}\; \rm g[/tex] per tablet.)
Explanation:
The relative atomic mass of an element is the ratio between:
the mass of one atom of this element, and the mass of one-twelfth of a carbon-[tex]12[/tex] atom.The definition of moles ensures that the relative atomic mass of an element is approximately numerically equal to the mass (measured in grams) of one mole of the atoms of this element.
The question states that the relative atomic mass [tex]A_{\rm r}[/tex] of iron is [tex]56[/tex]. In other words, the mass of one mole of iron [tex]\rm Fe[/tex] atoms would be approximately [tex]56\; \rm g[/tex].
The question is asking for the mass of some amount of [tex]\rm Fe^{2+}[/tex] ions. Each [tex]\rm Fe^{2+}\![/tex] ion contains two fewer electrons than a neutral [tex]\rm Fe[/tex] atom. Hence, [tex]4.2225 \times 10^{4}\; \rm mol[/tex] of [tex]\rm Fe^{2+} \![/tex] ions might be lighter than the same number of [tex]\rm Fe \![/tex] atoms by a very small extent: The mass of one mole of electrons is approximately [tex]5 \times 10^{-4}\; \rm g[/tex], much smaller than the mass of the same number of [tex]\!\rm Fe[/tex] atoms (approximately [tex]56\; \rm g[/tex].)
Estimate the mass of these [tex]4.2225 \times 10^{4}\; \rm mol[/tex] of [tex]\rm Fe^{2+}[/tex] ions using the mass of the same number of [tex]\rm Fe[/tex] atoms:
[tex]\begin{aligned}&m({\rm Fe^{2+}}) \\ &\approx m({\rm Fe}) \\ &\approx 4.2225 \times 10^{-4}\; \rm mol \\ &\quad\quad \times 56\; \rm g \cdot mol^{-1} \\ &\approx 2.3646 \times 10^{-2}\; \rm g \end{aligned}[/tex].
Five of these tablets would contain approximately [tex]5 \times 2.3646 \times 10^{-2}\; \rm g \approx 0.11823\; \rm g[/tex] of [tex]\rm Fe^{2+}[/tex] ions.
1. Why do you think it is so important to think about momentum in the NASCAR world? Use the
equation for momentum (momentum = mass times velocity) in your answer. (Hint: NASCAR
drivers drive really fast.] 1 point
Answer:
because it is
Explanation:
simple
Answer:
Explanation: none
Please help :)
It’s a science thing for 7th grade
Answer: The first question is chemical The second one is Physical
Explanation:
A beaker contains a sample of water with a mass of 325 grams. The water in the beaker
is boiled and weighed again after it cools. The new mass of the water is 305 grams. In
this example of the conservation of matter in physical changes,
A. the mass is less after it cools because water has less mass as a gas.
B. the mass of the water was 305 grams and the mass of the water vapor was 20 grams.
C. the process of boiling destroyed 20 grams of the water and left 305 grams of water.
D. the heat energy created by boiling water makes up the rest of the mass.
Answer: a
Explanation:
Bc I just did it and yeah
Name
12. A chemist places a piece of solid magnesium in an aqueous solution of copper (II)
sulfate and notices a reaction. Pieces of solid copper dropped out of the solution as a
precipitate and magnesium sulfate was formed.
a) Give a balanced formula equation (with state symbols) for this reaction (3 marks)
Answer:
Explanation: Mg(s) + CuSO4 (aq) -> Cu(s) + MgSO4 (aq)
Height
O
Genetic
O Environmental
O Both
Answer:
its both because your hight can change if u do exercises
Hope it helped.
Which of the following have London dispersion forces?
a. methane
b. carbon tetrachloride
c. bromine trifluoride
d. all of the above
Which of the following can be used as lubricant
Answer:
Explanation:
B is the ans
pls mark BRAINLIEST
I need help no links please
Answer:
A. We still feel gravity because of inertia, which occurs all around us. Gravity is not felt as much because although it feels small, gravity is the attraction that keeps objects on Earth.
B. This is due to a field and a law, which states that opposites attract and like repel.
A water solution containing an unknown quantity of a
nonelectrolyte solute is found to have a freezing point of
–0.23°C. What is the molal concentration of the solution?
Answer:
The molal concentration of the solution is approximately 0.124 molal
Explanation:
The given parameters are;
The reduced freezing point of the water = -0.23°C
For freezing point depression of a solution, we have;
[tex]\Delta T_f[/tex] = [tex]K_f[/tex]· b·i
Where;
[tex]\Delta T_f[/tex] = The freezing point depression
[tex]K_f[/tex] = Cyroscopic constant (The freezing-point depression constant) = 1.86° Cm⁻¹ for water
b = The molality of the solution
i = van't Hoff factor = 1
Therefore;
[tex]\Delta T_f[/tex] = [tex]T^{\circ}_f - T_f[/tex]
Where;
[tex]T^{\circ}_f[/tex] = The freezing point of pure water = 0°C
[tex]T_f[/tex] = The freezing point of the solution = -0.23°C
∴ [tex]\Delta T_f[/tex] = [tex]T^{\circ}_f - T_f[/tex] = 0°C - (-0.23°C) = 0.23 °C
From, [tex]\Delta T_f[/tex] = [tex]K_f[/tex]· b·i, we have;
0.23°C = 1.86°C/m × b × 1
∴ b = (0.23°C/1.86°C/m) ≈ 0.124 molal
Therefore, the molal concentration of the solution, b ≈ 0.124 molal.
What type of chemical reaction is demonstrated by this equation? A+BX-AX+B
Answer:
d an acid - base reaction.
Explanation:
Answer:
single replacement
Explanation:Look it up and got it from quizlet it should be right.
Lunar Eclipse. Choose ALL that apply
Question 1 options:
Earth casts its shadow on the moon
The moon turns dark
Light from the sun is blocked
Earth is directly between the moon and sun
Question 2 (0.5 points)
Solar Eclipse: Choose ALL that apply
Question 2 options:
The Earth is directly between the moon and sun
Earth casts a shadow on the moon
Moon moves between the sun and Earth
The moon blocks out the light of the sun and casts a shadow onto the Earth
In this exercise we have to use the knowledge of lunar eclipse to identify the alternatives that correspond to this effect, as follows:
Light from the sun is blockedEarth is directly between the moon and sunWhat is lunar eclipse?A lunar eclipse happens when the Earth is between the Moon and the Sun, at times when they are aligned. Depending on the position of the Moon, it is total, partial or penumbral. Different stages of a lunar eclipse on a full moon night.
Now, use the knowledge of solar eclipse to identify the alternatives that correspond to this effect, as follows:
Moon moves between the sun and EarthThe moon blocks out the light of the sun and casts a shadow onto the EarthWhat is the definition of solar eclipse?Solar eclipse is an astronomical phenomenon that occurs when the Moon is positioned between the Earth and the Sun, hiding the light emitted by the star towards the planet.
See more about eclipse at brainly.com/question/25105283
Explain your observations in term of how tempurature affects paritcle motion and how liquid changes to a solid
Answer:
See explanation
Explanation:
Temperature is defined as a measure of the average kinetic energy of the molecules of a body.
When a substance is heated, the kinetic energy of its molecules increases as the temperature increases; hence the particles of the substance moves faster with increasing temperature.
When heat is withdrawn from a liquid, the temperature decreases and the average kinetic energy of the molecules decreases. The molecules become less energetic hence the liquid changes into solid
help asap i don’t understand at all lol
Answer:
a, to reduce air bubbles
Explanation:
all its asking, is what is the purpose of the cover. and a is the most reasonable out of all of them, even though none of them make any sense.
2N2 + 502 --> 2N205
Based on the above reaction, if 7 moles of Ny react completely, how many moles of Oz must also react?
ASAP LOOK AT PICTURE
Answer:
wait are you talking about the bottom question??
4. A girl walked for 30 minutes. She noticed that she traveled farther in the first 15 minutes of
her walk than in the second 15 minutes,
What can she conclude about her walk?
A she walked over many hills
B
her average speed was faster during the first part of her walk
C. she walked in two different directions
D. she was walking at a constant speed
Which of the following elements would have the greatest attraction for
electrons? *
Rb
sr
Cs
Ba
Answer:
Sr
Explanation:
because it's electronegativity is the highest.
If peanut butter wasn't called peanut butter.. what would it be called?
Answer:
I have no idea
Explanation:
Which statement describes the solar feature shooting off into space labeled C?
An envelope of plasma surrounding the sun
A stream of glowing gas that shoots out from the sun in an arch
A brief eruption of intense high-energy radiation from the sun's surface
A dark spot appearing from time to time on the sun's surface
HELP 50 POINTS IF YOU DO IT RIGHT NOW
How much energy is released when 944.3 g of phosphoric acid is produced
P4O10(g) + 6H20(l) -- > 4H3PO4(aq)+424 kj
Answer:
1024.84 Kj
Explanation:
P₄o₁₀(g) + 6H₂O(l) => 4H₃PO₄(aq) + 424Kj
moles H₃PO₄ = (944.3g H₃PO₄) /(97.994g H₃PO₄ /mole H₃PO₄)
= 9.64 moles H₃PO₄
From equation reaction ratios ...
4 moles H₃PO₄ => 424 Kj
9.64 moles H₃PO₄ => (?)
4 moles H₃PO₄/9.64 moles H₃PO₄ = (424Kj)/(?)
Energy Released (Kj) = (424Kj)(9.64moles)/(4moles) = 1021.84 Kj
Two parent reproduction involves cell division that includes ___________? *
Meiosis
Fibrosis
Mitosis
Answer:
Mitosis
Explanation:
Enrichment of nuclear fuel 2 points A. increases the relative concentration of uranium-235 to 3-20% to produce energy in a power plant. B. increases the relative concentration of uranium-235 to 30-50% to avoid a nuclear explosion at higher percentages. C. increases the relative concentration of uranium-235 from 60% to 90% to achieve maximum electricity generation D. decreases the relative concentration of uranium-235 from 100% to 30-50% to avoid a nuclear explosion at higher percentages.
Answer:
B. increases the relative concentration of uranium-235 to 30-50% to avoid a nuclear explosion at higher percentages.
Explanation:
Uranium enrichment may be defined as a process which is necessary for creating effective nuclear fuel from the mined uranium by mainly increasing the percentage of the uranium-235 that undergoes fission with a thermal neutrons.
The enrichment process removes the unwanted uranium-238, thus making uranium 235 concentration higher. It takes up much work to increase the relative concentration of the uranium 235 to make it 30% to 50% so as to avoid a nuclear explosion at such higher percentages.
The graphic represents the Milky Way galaxy.
Which label best represents the location of our solar system within the milky way galaxy?
A
B
C
D
Answer:
planets,meteoroids and asteroids
Explanation:
What is the speed of a bird that flies 25 meters in 25 minutes?
Answer:
1mpm(1 meters per minute) Explanation: Speed:Distance/time 25/25=1 plz mark as brainliest
Answer:
1mpm(1 meters per minute)
Which of the following arrangements of electrons represent Potassium? *
a. 2,6,3,8
b. 2,7,8,2
c. 2,8,8,1
d. 2,9,7,1
What happens to pressure if temperature increases? Pressure increases. Pressure stays the same. Pressure decreases. Temperature has no effect on pressure.
Answer:
Pressure increases
Explanation:
According to Gay-Lussac's law, the pressure of a given amount of gas is directly proportional to the temperature at a given volume i.e.
[tex]P\propto T[/tex]
It means the relationship between the pressure and the temperature is direct.
If the temperature increases, the pressure of the gas also increases. Hence, the correct option is (A).
A plastic bag containing 2.2 L of gas at
1.0 atm pressure is cooled from 30°C to
0 °C. What will be the volume of the gas?
Answer: The volume of the gas is 1.98 L.
Explanation:
To calculate the final volume of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]
where,
[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.
[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.
We are given:
[tex]V_1=2.2L\\T_1=30^oC=(30+273)K=303K\\V_2=?\\T_2=0^0C=(0+273)K=273K[/tex]
Putting values in above equation, we get:
[tex]\frac{2.2}{303}=\frac{V_2}{273}\\\\V_2=1.98L[/tex]
Thus the volume of the gas is 1.98 L
Calcium carbonate decomposes into
calcium oxide and carbon dioxide.
The mass of calcium carbonate that
decomposes is 57 g. At the end of
the experiment, the mass of the
products were only 45 g. What can
we conclude from this information?
Answer:
The mass of carbon dioxide formed is 12g.
Calculate the percentage composition of sugar, C12H22011.
Answer:
%C= 42.1
%H=6.5
%O=51.4
Explanation:
Mass%=(mass/total)× 100%