[OH⁻] = 0.158 x 10 ⁻⁷ M is the concentration of OH- of a solution with an H3O⁺ concentration equal to 6.31 x 10 ⁻⁷ M.
What is pH scale ?The letters pH stand for the power of the hydrogen ion. The pH of a solution is the negative logarithm of the hydrogen-ion concentration.
pH = - [log H⁺]
[tex]\rm [H^{+}] [OH^{-}] = 1 \times 10^{-14}[/tex]
[tex]\rm[OH^{-}] = \dfrac{1 \times 10^{-14} }{ [H^{+}] }[/tex]
[tex]\rm[OH^{-}] = \dfrac{1 \times 10^{-14} }{ 6.31 \times 10^{-7} }[/tex]
[OH⁻] = 0.158 x 10 ⁻⁷ M
Therefore [OH⁻] = 0.158 x 10 ⁻⁷ M is the concentration of OH- of a solution with an H3O+ concentration equal to 6.31 x 10 ⁻⁷ M.
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The magnetite has a mass of
42.0 g and a volume of 8.1 cm3.
What is the density of the
magnetite sample?
Answer:
5.185 gcm⁻³
Explanation:
The formula to find density is:
Density = [tex]\frac{mass}{volume}[/tex]
Density = [tex]\frac{42}{8.1}[/tex]
Density of magnetite sample = 5.185 gcm⁻³
Answer: 5.185
Explanation: the formula to find the density is
Density = mass/volume
Density = 42/8.1
Density of magnetite sample = 5.185 g/cm3
A buffer solution made from a generic acid (HA with Ka =4.82 x 10-5 )is 0.110 M in HA and 0.110 M in NaA. How many moles of NaOH can 200 mL of this buffer neutralize before the pH rises by 0.50?
0.634 mol of NaOH can 200 mL of this buffer neutralize before the pH rises by 0.50.
What is a buffer solution?A buffer is a solution that can resist pH change upon the addition of an acidic or basic components.
Solution:
A buffer consists of 0.11 M HA and 0.11 M NaA.
Ka =[tex]4.82 X 10^-^5[/tex]
pKa = -log ([tex]4.82 X 10^-^5[/tex])
pKa = 11.83
Using Henderson equation to calculate pH of the buffer solution.
pH =PKa -log [tex]\frac{Conjugate \;base}{Acid}[/tex]
pH = 11.83 - [tex]\frac{0.11 M}{0.11 M}[/tex]
pH = 10.83
pOH = 14 - 10.83
pOH = 3.17
Calculating the moles of NaOH added by the addition of 200 mL
Molarity = [tex]\frac{Moles \;of \;NaOH}{0.2 L}[/tex]
3.17 X 0.2 = Moles of NaOH
Moles of NaOH = 0.634 mol
Hence, 0.634 mol of NaOH can 200 mL of this buffer neutralize.
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Scientists use models to
A - Stop the occurrence of tsunamis due to an earthquake
B - Predict the damages due to an earthquake
C - Change the location of a volcanic eruption
D - Increase the duration of a volcanic eruption
Hii!
Explain Rutherford's model.
Answer:
Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. This model of an atom was developed by Ernest Rutherford, a New Zealand native working at the University of Manchester in England in the early 1900s
Explanation:
yan na ang exact
Rutherford's atomic model is the model which described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons, circulate at some distance, much like planets revolving around the Sun.
how does air pollution cause global warming
Answer:
Air pollution affects the compounds in the air, causing heat to change dramatically over time in the atmosphere.
WILL GIVE BRAINLIEST!
A certain reaction is endothermic in the forward direction. The reaction has less moles of gas on the product side. Which of the following stresses would increase the yield of the products (shift right)?
•Decreasing the temperature
•Decreasing the reactant concentration
•Increasing the volume
•Increasing the pressure
answer is either A or D
Answer:
A
Explanation:
Increasing the the temperature would favour the endothermic reaction which is the forward direction however increasing the pressure would make the reaction try to counteract this change by favouring the reaction that would create more products so the equilibrium will shift left instead of right.
Hope this helps.
___Cu2S (s) + ___O2 (g) → ___Cu (s) + ___SO2 (g)
A. Balance the chemical equation above.
B.hat type of reaction is/are being represented by the chemical reaction in part (a)?
Answer:
(a)Cu2S(s) + O2(g) --> 2Cu(s) + SO2(g)
(b) single displacement reaction
Na-23 has 11 protons.How many neutrons does it have?
this is how you find it:
23-11=12
the 12 is the amount of neutrons
Plants such as _______________ provided much nitrogen to the soil.
Answer:
Abiotic
Explanation:
Its because it includes water, sunlight, tempature and soil
6.45g of lithium reacts with 9.2g of oxygen gas to produce lithium oxide.How many grams of Li20 are formed? Hint: write the balanced chemical equation first.
A mixture of hydrogen (2.02 g) and chlorine (35.90 g) in a container at 300 K has a total gas pressure of 748 mm Hg. What is the partial atmospheric pressure (atm) of hydrogen in the mixture?
The partial atmospheric pressure (atm) of hydrogen in the mixture is 0.59 atm.
How do we calculate the partial pressure of gas?Partial pressure of particular gas will be calculated as:
p = nP, where
P = total pressure = 748 mmHgn is the mole fraction which can be calculated as:n = moles of gas / total moles of gasMoles will be calculated as:
n = W/M, whereW = given massM = molar massMoles of Hydrogen gas = 2.02g / 2.014g/mol = 1 mole
Moles of Chlorine gas = 35.90g / 70.9g/mol = 0.5 mole
Mole fraction of hydrogen = 1 / (1+0.5) = 0.6
Partial pressure of hydrogen = (0.6)(748) = 448.8 mmHg = 0.59 atm
Hence, required partial atmospheric pressure of hydrogen is 0.59 atm.
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Look at the equation. Which is the Brønsted-Lowry base?
Answer:
the answer is H3O+.......
Answer:
H₂O
Explanation:
A Brønsted-Lowry base accepts protons. As seen in the equation, H₂O gains a proton to become H₃O⁺. It has gained one proton- a hydrogen atom.
C₂H₃O₂⁻ is a conjugate base.
H₃O⁺ is a conjugate acid.
HC₂H₃O₂ is an acid [or a Brønsted-Lowry acid].
A 49.2 g sample of barium hydroxide is dissolved in water and the solution is diluted to give a final volume of 629.84 mL. What is the final molarity of the solution?
Answer:
.455 M
Explanation:
Ba (OH)^2 has mole weight of (from periodic table) = 171.341 gm/mole
49.2 gm / 171.341 gm/mole = .287 mole
.287 M / .62984 L = .455 M
How can glass be a liquid if it's so hard?
Answer: below
Explanation:
Glass can be heated up and turn into a liquid, its a hard procces, due to the extreme heat, machines are used today.
Answer:
answer
[tex]\huge\tt{\underline{\colorbox{maroon}{✨ANSWER}}}[/tex]
Explanation:
Because glass is hard, it must be a supercooled liquid. Glass, however, is actually neither a liquid—supercooled or otherwise—nor a solid. It is an amorphous solid—a state somewhere between those two states of matter
Calculate the volume(mo) of 0.50 M NaCl stock solution need to make 100mL of a diluted solution with a concentration of 0.03
Answer:
.006L or 6 mL
Explanation:
The concentration of a solution refers to the amount of solute that has been dissolved in a given amount of solute. consider the solution seen. here select all the ways that this solution could be made more concentrated.
A.) increase the amount of solute
B.) decrease the amount of solute
C.) decrease the amount of solvent
D.) increase the amounts of solute and solvent
A force of 20 N
acts upon a 5 kg
block. Calculate
the acceleration
of the object.
Answer:
0.25m/s²
Explanation:
here
weight(w)-20 N
mass(m)-5 kg
acceleration (g) -?
we know
w=mg
g=m/w
=5/20
=0.25 m/s²
Answer:
acceleration=0.04g/s
Explanation:
force=Ma
20N=5kgXa
5kg=5000g
20N=5000Xa
20N=5000a
divide both sides by 5000
acceleration=0.04g/s
I will mark as brainliest if correct
Which of the following is described by the equation H2O(l) --> H2O(s) + heat?
A. Melting
B. Condensing
C. Freezing
D. Evaporating
Answer:
[A] Melting
Explanation:
From the giving it means:
H2O(s) - Solid {Ice}
H2O(l) - Liquid {water}
So the equation is:
Liquid ⇒ Solid + Heat
Water ⇒ Ice + Heat
Hence, if you add ice and heat it equal to melting.
Therefore the correct answer is [A] Melting.
Kavinsky
Answer: C. Freezing
Explanation:
CH3-CH=CH3-CH what is the name of this structure?
Answer:
if you meant CH3-CH=CH-CH3, the IUPAC name is 2-butene.
Which statement(s) about neutrons is/are TRUE?
SELECT ALL THAT APPLY
The major clue to their existence was extra mass in
a atoms that protons and electrons could not
account for.
b They were observed and measured directly, like
protons and electrons were.
C They have the same mass as protons.
d They have a negative charge.
Answer:
C
Explanation:
Because D ask "They have a negative charge" yes and no, but neutrons do, Why? Well because the neutron has a negative charge both in its inner core and its outer edge, with a positive charge sandwiched in between to make the particle electrically neutral. Whilst B is wrong because like protons and electrons they were both measured and observed differently, just as the neutron. So that makes C the only correct answer.
Calculate the pH of the following solutions at 298 K.
a) 0.25 mol dm-3 HCl.
b) 0.15 mol dm-3 H2SO4.
c) 0.15 mol dm-3 benzoic acid. Ka(benzoic acid) = 6.4 x 10-5 mol dm-3.
d) 0.10 mol dm-3 KOH. Kw(298 K) = 1.0 x 10-14 mol2 dm-6.
The term pH has to do with the hydrogen ion concentration of a solution.
What is pH?The term pH has to do with the hydrogen ion concentration of a solution. Let us now proceed the pH of the solutions;
a) pH of HCl = -log(0.25) = 0.62
b) pH of H2SO4 = -log(0.15) = 0.82
c) We have to set up an ICE table here;
C6H5COOH + H2O ⇄ C6H5COO- + H^+
I 0.15 0 0
C -x +x +x
E 0.15 -x x x
Ka = [C6H5COO-] [ H^+]/[C6H5COOH]
6.4 x 10^-5 = x^2/0.15 - x
6.4 x 10^-5(0.15 - x) = x^2
9.6 * 10^-6 - 6.4 x 10^-5x = x^2
x^2 + 6.4 x 10^-5x - 9.6 * 10^-6 = 0
x=0.003 M
Hence;
[C6H5COO-] = [ H^+] = x = 0.003 M
pH = - log[0.003 M] = 2.5
d) [OH-] [H^+] = 1.0 x 10-14 mol2 dm-6
[H^+] = 1.0 x 10-14 mol2 dm-6/ 0.10 mol dm-3
[H^+] = 1 * 10^-13 M
pH= - log[1 * 10^-13 M] = 13
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Net ionic equation for Calcium hydroxide reacting with ammonium Chloride?
Answer:
Step 1: Write the balanced chemical equation with the states first:
Ca(OH)₂ (aq) + 2NH₄Cl (aq) → CaCl₂ (aq) + 2NH₃ (g) + 2H₂O (l)
Step2: Write the complete ionic equation, break only the aqueous ones only :
Ca²⁺ + 2OH⁻ + 2NH₄⁺ + 2Cl⁻ → Ca⁺² + 2Cl⁻ + 2NH₃ (g) + 2H₂O (l)
Step 3: cancel the spectator ions ( the ions which stay the same like calciumn and chlorine ions here)
2OH⁻ + 2NH₄⁺ → 2NH₃ (g) + 2H₂O (l)True or False - Elemental gases are relatively insoluble in water and should be given the state (g).
Answer:
True
Explanation:
I assume this is refering to gases such as O2, H2, I2, F2, ect. And possibly the nobel gases which are completly insoluable. As gases they should be given the state (g).
Elemental gases are relatively insoluble in water and should be given the state (g). The given statement is true.
An example of elemental gas is Helium (He).
Helium belongs to the class of noble gases, these elements are defined by their low reactivity, also as gases, they do not have color or odor. Helium is part of this group that contains other 5 elements because Helium characteristics are similar to other noble gases, indeed this is the first noble gas in the periodic table. Additionally, helium is an abundant element found in all the universe especially in stars. Helium gas is used to fill balloons.
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When was electricity invented?
Answer:In 1752
Explanation:Benjamin franklin in 1752 to prove that lightning was electrical,he flew a kite during a thundorstorm.He tied a metal key onto the string and as he suspected it would ,electrically from the storms clouds flowed down the string ,which was wet and he received an electrical shock.
Electricity was discovered and understood by many scientists. Benjamin Franklin is given the credit for discovering electricity. In the year 1752, Benjamin Franklin conducted an experiment using a kite and key on a rainy day.
You are standing outside in a rural area at night, looking up to the sky and observe many stars. If you were to look up to the sky in the city on that exact same night, what would you observe? (2 points)
Group of answer choices
That only the street lights shine in the sky
That there appears to be little to no stars in the sky
That there appears to be many stars in the sky
Answer:
That there appears to be many stars in the sky
Explanation: hope this helps! <33333
If you add 5.9 mL 4.00 mL of pure water to 28.752 mL 6.00 mL of 0.56 M 0.750 M NaCl solution, what is the concentration of sodium chloride in the diluted solution?
pick one volume and concentration as a sample
5.9 ml + 28.752 ml = 34.652
M1V1=M2V2
0.56 x 28.752 = M2 x 34.652
M2=0.464 M
A sodium chloride solution with a Molarity of 0.239 M has a volume of 158 mL. How many grams
of solute are in the solution?
Answer:
2.21 grams
Explanation:
The first thing you need to do is find the chemical formula for sodium chloride which is NaCl (Molar mass: 58.44 g/mol).
The next the thing to do is to convert the mL to L by dividing by 1000 which will give us 0.158 L.
Now we look at the molarity formula M = n/L, plug in the molarity for M and the liters for L. 0.239 M (mol/L) = n/0.158 L.
Solve for n to get the number of moles of NaCl in the solution. You should get 0.037762 moles.
Then we have to multiply this by the molar mass of NaCl, (0.037762 mol)*(58.44 g/mol).
Moles cancel and when we round to sig figs we are left with 2.21 grams.
Hope this helps.
An element P with electron configuration 2,
8, 2 combined with another element Q with
electron configuration 2, 8, 7. The chemincal
bond between P and Q is
A. covalent B. coordinate
C. metallic D. electrovalent
Answer:
Electrovalent.
Explanation:
[tex]\text{The element P is }~ _{12}Mg\\\\\text{The element Q is }~ _{17}Cl\\\\\text{The chemical bond between P and Q is ionic or electrovalent bond.}\\\\Mg^{2+} + 2\text{Cl}^{-} \rightleftharpoons MgCl_2[/tex]
13 a plant will start to wilt/sprout without sunlight
Answer:
wilt
Explanation:
Without sunlight, photosynthesis cannot occur, and photosynthesis makes chlorophyll, the plant's food. Therefore, a plant without sunlight will "starve," and begin wilting.
Answer:
it will true
Explanation:
The energy diagram shows the changes in energy during a chemical reaction.
Which statement best describes the total energy change of the system?
Potential energy
M
Reaction progress
O A. The reactants have higher potential energy, and energy is released.
O B. The reactants have lower potential energy, and energy is released.
O C. The reactants have lower potential energy, and energy is
absorbed.
O D. The reactants have higher potential energy, and energy is
absorbed.
There is no diagram attached but there are some ways by which you can find it too easily by yourself
Usually energy diagram uses ∆H .
So
If ∆H is +ve means reaction is exothermic and energy is releasedIf ∆H is -ve means reaction is endothermic and energy is absorbedSo observe∆H whether it. is decreasing or increasing ,
If increasing then energy is being released and vice versa