Answer:
Number of elements= 2
Number of subscripts= 1
Number of of atoms= 5
What is the coefficient? - C. 5
When [H+] = 4.0 × 10–9 M in water at 25°C, then
Kw =1.0×10–14.
b. pOH = 7.
c. [H3O+] = [OH–].
d. pH= 7
e. A-D are all correct
Answer:
a. Kw = 1.0 × 10⁻¹⁴
Explanation:
a. Let's consider the self-ionization of water.
2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻
The ion-product of water (Kw) at 25 °C is:
Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴
c. Considering [H⁺] = [H₃O⁺] = 4.0 × 10⁻⁹ M, the concentration of OH⁻ is:
[OH⁻] = 1.0 × 10⁻¹⁴/[H₃O⁺] = 2.5 × 10⁻⁶ M
b. We can calculate the pOH using the following expression.
pOH = -log [OH⁻] = -log 2.5 × 10⁻⁶ = 5.6
d. We can calculate the pH using the following expression.
pH = -log [H⁺] = -log 4.0 × 10⁻⁹ = 8.4
When [H+] = 4.0 × 10–9 M in water at 25°C, then the [tex]Kw =1.0\times 10^-^1^4.[/tex]
What is dissociation constant?
Kw is the dissociation constant or ionization constant of water.
The self-ionization of water will be
[tex]\rm 2 H_2O(l) = H_3O^+(aq) + OH^-[/tex]
The dissociation constant of the water at 25°C will be
[tex]\rm Kw = [H_3O^+][OH^-] = 1.0 \times 10^-^1^4[/tex]
Thus, the correct option is a. [tex]Kw =1.0\times 10^-^1^4.[/tex]
Learn more about dissociation constant
https://brainly.com/question/3657057
What pH scale number represents a neutral.
What pH scale number represents a neutral.
The answer is 7
how many elements are found in the third period. A.2 B.18 C.8 D.32
Answer:
8
Explanation:
u can find it on ur chemistry book
Answer:
C. 8
Explanation:
Check chemistry textbook
A chemist combine did 3.50g of potassium level with chlorine gas to yield 6.6 7g of potassium for it. Assuming all the potassium was consumed, and that potassium chloride was the only product that formed, what mass of chlorine reacted?
Answer: mass of chlorine reacted is 3.18 g
Explanation:
2 K + Cl2 = 2KCl
no. of moles of K = mass / molar mass
= 3.50 / 39
= 0.0897
no. of moles of KCl = mass / molar mass
= 6.67 / 74.5
= 0.0895
no. of moles of Cl2 required = number of moles of KCl / 2
= 0.0895 / 2
= 0.0448 moles
mass of Cl2 required = no. of moles of Cl2 required x molar mass
= 0.0448 x 71
= 3.1808 g ≈ 3.18 g
Therefore mass of chlorine reacted is 3.18 g
What is the atomic radius
Answer:
The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons.
What is an nucleus ?
Nucleus is present at the centre of atom. It contains protons and neutrons. It is very small as compared to the atom.
Answer:
It is a part of a cell which controls all the activities in the cells and contains the genetic information of the cell that is to be passed down to the next cell when it reproduces.
Explanation:
It is a part of a cell which controls all the activities in the cells and contains the genetic information of the cell that is to be passed down to the next cell when it reproduces.
When circumstances are right, most materials undergo a process called thermal expansion. Which statement best describes the cause and effect of thermal expansion? Group of answer choices Matter is heated, and its particles spread out more. Matter is heated, and its particles move closer together. Matter is cooled, and its particles move closer together. Matter is cooled, and its particles spread out more.
Answer: Matter is heated, and its particles spread out more
Explanation:
Thermal expansion occurs when there's an expansion of an object or material or when an object becomes bigger because of a rise in its temperature. This brings about the faster movement of the heated molecules and the atoms spreading out.
Therefore, the cause and effect of thermal expansion will be that when matter is heated, and its particles spread out more.
HELP!!
IF YOU DON'T KNOW THE ANSWER DON'T ANSWER!
Answer: increase
Explanation:
ahhhhhhhhhhhhhhh
In the reaction __S+3O2→2SO3, what coefficient should be placed in front of the S to balance the reaction?
Question 1 options:
1
2
3
Answer:
2
Explanation:
because on the product side you have 2 sulfurs so you need 2 on the reactant side.
____________ sedimentary rocks form from the remains of living things.
a.
organic
c.
detrital
b.
chemical
d.
foliated
Answer:
I believe the answer is A. Organic.
Hope it helps!
Answer:
Organic
Explanation:
living things are organic, so chemical is wrong, detrital is when rocks form from broken down rocks left behind, again not from living things so that's also wrong, that leave Organic and foliated, foliated makes no sense which leave only Organic, so organic will be your answer
Atom and Periodic table vocabulary:
1. The mass on the periodic table.
2. Particles that differ in number between isotopes.
3. Vertical column in the periodic table.
4. Atoms of the same element that have different masses.
5. All elements in the same one of these has the same number of energy levels in their electron cloud.
6. The smallest form of matter that still retains the properties of an element.
key:
Neutrons
Quark
Average atomic mass
Isotopes
Group
Period
Answer:
1. The mass on the periodic table.
Average atomic mass
2. Particles that differ in number between isotopes.
Neutrons
3. Vertical column in the periodic table.
Group
4. Atoms of the same element that have different masses.
Isotopes
5. All elements in the same one of these has the same number of energy levels in their electron cloud.
Period
6. The smallest form of matter that still retains the properties of an element.
Quark
Explanation:
what is meant by the term quantitative?
A) number measurement
B) words & explanation
Answer:
a) number measurement
Explanation:
relating to, measuring, or measured by the quantity of something rather than its quality.
Answer:
number and measurement
Explanation:
Quantitative is an adjective that simply means something that can be measured. For example, we can count the number of sheep on a farm or measure the gallons of milk produced by a cow.
Four students rolled a ball down a slide on the play ground which ball has the greatest applied force
CAN YOU PLZ HELP ME ITS TIMED BRAINLIEST!
ONLY ANSWER IF YOU KNOW THE ANSWER PLZ!
The diagram shows two chromosomes paired up.
Which process is being shown?
sexual reproduction
independent assortment
crossing over
chromosome separation
Answer:
the sexual reproduction
Explanation:
Which cools faster, magma or lava?
lava
magma
they both cool in seconds
Answer:
lava
Explanation:
balance the chemical equation KC1O3→KC1+O2
Answer:
2 KCO3 → 2 KC + 3 O2
Explanation:
Reaction Type
Decomposition
Reactants
KCO3
Products
KC
Dioxygen - O2
O₂ Oxygen Molecular Oxygen Diatomic Oxygen Triplet Oxygen Oxygen Gas Liquid Oxygen LOx
can copper be scratched by a fingernail or blade knife. why?
Answer:
it could by blade knife
Explanation:
fingernail has hardness 2.5; copper penny, about 3.5; a knife blade, 5.5
which formula represents a nonpolar molecule containing polar covelant bond
Answer: H2O and NH3 are polar molecules. H2 is a nonpolar molecule but the H-H bond is also nonpolar.
Therefore, the best choice is CCl4. Although the C-Cl bond is polar due to electronegativity differences, the molecule itself is nonpolar because the net dipole moments cancel out, given its tetrahedral molecular structure.
Explanation:
What is the mass of 1.00 mol of oxygen (O2)?
Answer:
Mass = 32 g
Explanation:
Given data:
Number of moles of oxygen = 1.0 mol
Mass of oxygen = ?
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of oxygen (O₂) is 32 g/mol
by putting values,
1.0 mol = mass/ 32 g/mol
Mass = 1.0 mol ×32 g/mol
Mass = 32 g
NEED HELP ASAP!!! I just need to know the order
Chlorine monoxide accumulates in the stratosphere above Antarctica each winter and plays a key role in the formation of the ozone hole above the South Pole each spring. Eventually, ClO decomposes according to the equation:
The question is incomplete, the complete question is;
Chlorine monoxide accumulates in the stratosphere above Antarctica each winter 3nd plays a key role the formation of the ozone hole above the South Pole each spring Eventually. CIO decomposes acco to the equation: 2CIO(g) rightarrow CL2(g) + O2(g) The second-order rate constant for the decomposition of CIO is 6950000000 M-1 s-1 at a particular temperature Determine the half-life of CIO when its initial concentration is .0000000185 M
Answer:
7.8 * 10^-3 s
Explanation:
Given that the half life of a second order reaction is obtained from the formula;
t1/2 = k-1[A]o-1
t1/2 = 1/k[A]o
second order rate constant (k) = 6950000000 M-1 s-1
initial concentration ([A]o) =0.0000000185 M
t1/2 = 1/6950000000 * 0.0000000185
t1/2 = 7.8 * 10^-3 s
A 0.98 gram sample of a volatile liquid was heated to 348 k. the gas occupied 265 ml of space at a pressure of 0.95 atm. what is the molecular weight of this gas?
Answer:
The molecular weight is [tex]Z = 111.2 \ g/mol[/tex]
Explanation:
From the question we are told that
The mass of the sample is [tex]m = 0.98 \ g[/tex]
The temperature is [tex]T = 348 K[/tex]
The volume which the gas occupied is [tex]V = 265 \ ml = 265 *10^{-3} L[/tex]
The pressure is [tex]P = 0.95 \ atm[/tex]
Generally from the ideal gas equation we have that
[tex]PV = n RT[/tex]
Here n is the number of moles of the gas while the R is the gas constant with value [tex]R = 0.0821 \ atm \cdot L \cdot mol^{-1} \cdot K^{-1}[/tex]
[tex]n = \frac{PV}{ RT}[/tex]
=> [tex]n = \frac{ 0.95 * 265 *10^{-3} }{ 0.0821 * 348}[/tex]
=> [tex]n = 0.00881 \ mol[/tex]
Generally the molecular weight is mathematically represented as
[tex]Z = \frac{m}{n}[/tex]
=> [tex]Z = \frac{0.98 }{0.00881}[/tex]
=> [tex]Z = 111.2 \ g/mol[/tex]
Based on periodic trends which atom has a larger ionization energy then calcium Ca?
Answer:
Gallium, Germanium, Arsenic, Selenium, Bromine and Krypton
Explanation:
Based on periodic trends, the atom that has a larger ionization energy than calcium are Gallium, Germanium, Arsenic, Selenium, Bromine and Krypton.
Across the period, the ionization energy increases from left to right.
Ionization energy is the energy required to remove the most loosely held electron within an atom. As you go from left to right, the ionization energy increases rapidly.The elements to the right of Ca will have a higher ionization energy compared to Ca.Please help with this question..thank you
Which of the following is an example of potential energy? O A. The energy of vibrating air O B. The energy of moving particles O C. The energy in chemical bonds OD. The energy of a runner on a flat road
D
Explanation:
i hope so it is the answer
Which is a component of John Dalton’s atomic theory?
The ratio of atoms in a compound is fixed.
The atoms of different elements are the same.
An atom is a small particle of matter that can be broken down.
A reaction can create or destroy atoms as well as rearrange them.
Answer:
i think the answer is b
Explanation:
A teacher asks students to describe the physical properties of 10 mL of vinegar and 10 mL of milk. When the students finish listing the physical properties in their science notebooks, the teacher pours the vinegar and milk into the same beaker. The students are surprised to see a white solid substance form within the beaker as the two substances are combined.
What occurs within the beaker as the teacher mixes the vinegar and milk?
1. A chemical change that produces a precipitate
2. A physical change that creates a new substance
3. A physical change that produces a precipitate
4. A chemical change that produces no new substances
Answer:
1. A chemical change that produces a precipitate
Explanation:
A solid substance that is formed from a liquid phase is called a precipitate.
A reaction that produces a precipitate is called a precipitation reaction.
Precipitation reactions are an example of a chemical change.
Thus the correct answer is option 1: A precipitate was formed when vinegar and milk were mixed (as there were no solid substances when they were apart).
Help lol please lol thank you :)
Answer:
45
Explanation:
Answer:
45 lol
Explanation:
How many atoms of each element are in the chemical formula NH4NO2?
1 nitrogen, 1 hydrogen, and 3 oxygen
O 1 nitrogen, 4 hydrogen, and 3 oxygen
2 nitrogen, 4 hydrogen, and 3 oxygen
O 5 nitrogen, 1 hydrogen, and 1 oxygen
How many minutes will it take to plate out 4.50 g of Cu from a solution of Cu(NO3)2 (aq) onto the cathode of an electrolytic cell when 8.00 A of current are used?
a. 28.5 min.b. 3.06 × 10^−9 min.c. 14.2 min.d. 1.82 × 10^3 min.
Answer:
a. 28.5 min
Explanation:
The computation of the number of minutes would it take to plate out is as follows:
Cu+2 +2e [tex]\rightarrow[/tex]Cu
The two moles of electrons could be generated for the copper i.e. deposited
Now
moles of copper is
= 4.5 ÷ 63.5
= 0.071
The 63.5 represents the atomic copper weight
Now mole of electrons deposited is
= 0.071 × 2
= 0.142
Now
quantitiy of electricity needed
= moles of electrons deposited × 96500
= 0.142 × 96500
= 13703 coulums
As per electricity quantity needed
= current × time(seconds)
= 13703 = 8 × t
t = 13703 ÷ 8
= 1713 seconds
= 1713 ÷ 60 minutes
=28.5 min
hence, the correct option is a.