Answer:
See explanation
Explanation:
Energy of the photon;
E = hc/λ
h= Planks constant
c= speed of light
λ = wavelength
E= 6.6 × 10^-34 × 3 × 10^8/4 x10 -7
E = 4.95 × 10^-19 J
If 1ev=1.602x10-19 J
x = 4.95 × 10^-19 J
x= 3.1 ev
From Einstein's photoelectric equation;
KE = E - Wo
Where;
KE = kinetic energy of ejected photoelectron
E= energy of the photon
Wo= work function of the metal
KE = 3.1 eV - 2.13 eV
KE= 0.97 eV
KE = 0.97 eV × 1.602x10-19 J
KE = 1.55 × 10^-19 J
KE = 1/2 mv^2
1.55 × 10^-19= 1/2 × 9.1 × 10^-31 × v^2
v= √2 × 1.55 × 10^-19/9.1 × 10^-31
v= 5.8 × 10^5 m/s
please hurry which statement is a scientist most likely to use in describing work
Write the empirical formula for at least four ionic compounds that could be formed from the following ions: NO3, Pb^4+, NH4, SO4
Explanation:
here's the answer to your question
double arrow just mean that it's a reversible process, and the reaction can go back and forth.
Molar mass calculation for Cl^2
Answer:
Mass of Cl = 35.5
Mass of Cl2 => 35.5×2
=> 71 g/mol
hope that helps ✌
71
explain:The atomic mass of chlorine is equal to the molar mass of chlorine so the molar mass of chlorine is 35.5
=> molar mass for Cl^2: 35,5*2=71
relate the pH of a solution to its hydronium and hydroxyl ion concentration and its acidity or basicity
brain list if your answer is good
when ph decrease that means acidity increase
when ph increase that means basicity increase
What are 5 uses of nitrogen?
Answer:
nitrogen is used in the production of 1) fertilisers 2) nitric acid 3) nylon 4) dyes and 5) explosives
please give me brainliest if you can :))
UM UM UM HELP AGAIN. which of the following would increase the pressure of a gas
a. letting out air of an air mattress
b. taking a breath of air
c. lying on an air mattress
d. throwing a balloon into the air
Answer:
I think c) laying on an air mattress
WHICH STATEMENT BEST REPRESENTS A HYPOTHESIS
Answer:
D
Explanation:
Hypotheses are educated guesses, and the best answer is the one with an if, as it indicates that it's a guess.
Answer:
letter b should be the answer
Describe how to make a buffer solution using a strong base and one other reagent. 15 POINTSSSSSSSS
Answer:
Hi! hopefully this helps you
Explanation:
You can make a buffer solution for a specific pH (potential of hydrogen) by mixing together a weak acid like acetic acid HC2H3O2 with a salt that contains the conjugate base like sodium acetate NaC2H3O2. A neutralization reaction would occur as you are mixing a weak acid and a strong base.
When you add the base to an acidic solution, the solution becomes less acidic and moves toward the middle of the pH scale. Aka neutralization
Hope this helps! best of luck <3
Determine the mass of oxygen in a 45.0 g sample of calcium carbonate
Answer:
The mass of oxygen in 45.0 g sample of calcium carbonate is approximately 21.58 g
Explanation:
The chemical formula for calcium carbonate is CaCO₃
The molar mass of CaCO₃ = 100.0869 g/mol
The mass of oxygen in one mole of CaCO₃ = 3 × 15.999 g = 47.997 g
The mass of oxygen in 45.0 g sample of CaCO₃, m, is goven as follows;
m = 45.0/100.0869 × 47.997 g ≈ 21.58 g
The mass of oxygen in 45.0 g sample of calcium carbonate, m ≈ 21.58 g
please answer fast............
It's O2 which is oxygen....
Answer:
c. CO2 is the answer.Explanation:
Hope this helps you. Please mark as brainliest. Good Luck^_^
what is the anode material used in the extraction of aluminium by electrolysis and why it needs to be changed at interval
Answer:
the anode material is graphite(replaceable graphite rods).
The oxygen gas burns away the anode as Carbon dioxide therefore the anode must be replaced continuously.
What species is reduced in the reaction Fe + AgNO3 → Fe(NO3)3 + Ag?
A. Agt
B. Fe
C. NO3
D. Fe3-
The species that is reduced in the reaction is Fe. Option B
The process by which an atom gains an electron, thereby lowering or decreasing its oxidation number. Basically, the positive character of the species is reduced. Reduction occurs when an atom gains one or more electrons during a chemical reaction. This means that the oxidation number decreases. This is when an atom gains an electron because electrons have a negative charge.
Acquires a negative charge that reduces the oxidation number. Reduction involves a half-reaction in which a chemical species reduces its oxidation number, usually by gaining an electron. The other half of the reaction involves oxidation in which electrons are lost. Reduction and oxidation together form a redox reaction. As the oxidation number increases, the atom is oxidized, and as the oxidation number decreases, the atom is reduced.
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Answer: Ag+
Explanation: I just took the test.
A student was given a 2.850-g sample of a mixture of potassium nitrate and potassium bromide and was asked to find the percentage of each compound in the mixture. She dissolved the sample and added a solution that contained an excess of silver nitrate, AgNO3. The silver ion precipitated all of the bromide ion in the mixture as AgBr. It was filtered, dried, and weighed. Its mass was 1.740 g. What was the percentage of each compound in the mixture
Answer:
See explanation
Explanation:
The reaction occurs as follows;
KBr(aq) + AgNO3(aq) ----> AgBr(s) + KNO3(aq)
Number of moles of AgBr formed = mass /molar mass =1.740 g/187.77 g/mol = 0.0093 moles
From the reaction equation;
1 mole of KBr yields 1 mole of AgBr
Hence the number of moles of KBr reacted = 0.0093 moles
Mass of KBr present = 0.0093 moles × 119g/mol = 1.11 g
Mass of KNO3 = 2.850 g - 1.11 g = 1.74 g
Percentage of KBr = 1.11 g/2.850 g × 100 = 38.9%
Percentage of KNO3 = 1.74 g/2.850 g × 100 = 61.1%
05) Identify the statement that is true about atoms as they pass through the rock cycle. a. Those that were adjacent to each other remain near each other. b. They do not move through the rock cycle at the same rate. c. They move through the rock cycle in the same manner. d. They stay within the same mineral.
Answer:
b. They do not move through the rock cycle at the same rate
Explanation:
The rock cycle is the phenomenon used to describe the interrelation of the three forms in which rocks exists, and a rock is changed between forms due to the Earth's geologic process, such as erosion, weathering and plate tectonics
The rock cycle involves both chemical and physical transformation of rocks and therefore, the atoms and compounds make and cut connections, such that the rate at which each atom move through the rock cycle at different rate
A sample of lithium sulfate, (Li2SO4), has 2.94 x 1023 atoms
of lithium. How many moles of lithium sulfate is the sample?
Answer:
0.245 moles
Explanation:
moles of lithium = 2*moles of Li2SO4
so moles of LI2SO4=2.94*10^23/(2*6*10^23)=0.245
One mole of lithium sulphate contains 1.2 .022 × 10²⁴ atoms. Thus, the number of moles of this compound which contains 2.94 × 10²³ Li atoms is 4.08 moles.
What is one mole?Any substance containing 6 .022 × 10²³ number of atoms is called one mole of that substance. This number is called Avogadro number. Hence, one mole of every elements or molecules contains Avogadro number of atoms.
Similarly, one mole of any compound contains 6 .022 × 10²³ molecules. The weight of one mole of a compound is called its molar mass. The mass of one mole of an element is called its atomic mass.
Hence, one mole of lithium sulphate contains 2 × 6 .022 × 10²³ atoms of lithium. Therefore, the number of moles of lithium sulphate containing 2.94 × 10²³ Li is :
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What is the meaning of salt
Answer:
a white crystalline substance that gives seawater it characteristics of taste
describe the different system of measurement
Answer:
A system of measurement is a collection of units of measurement and rules relating them to each other. ... Systems of measurement in use include the International System of Units (SI), the modern form of the metric system, the British imperial system, and the United States customary system.
Explanation:
Hope it works!!!!
Answer:
Systems of measurement in use include the International System of Units (SI), the modern form of the metric system, the British imperial system, and the United States customary system.
Water glass is found in
A. Liquid form at room temperature
B. solid state at room temperature
c. semi liquid form at room temperature
D. None of above
Answer:
liquid form
Explanation:
am i right? if right like
Answer:
semi-liquid at room temperature
Which reaction occurs at the cathode in an electrochemical cell?
A. Cu(s) → Cu2+(aq) + 2e
B. Cu2+(aq) + H2(g) → Cu(s) + 2H+(aq)
C. Cu(s) + 2H+(aq) → Cu2+(aq) + H2(g)
D. Cu2+(aq) + 2e → Cu(s)
Answer:
I could be wrong but I say it's letter b
Explanation:
I hope you have an great night
What is the name for the compound li2so4
Answer:
Explanation:
Lithium Sulphate
Answer:
Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid.
A sample of oxygen gas has a volume of 453.7 mL when its pressure is 0.435 atm. What will the volume of the gas
be
at a pressure of 0.88 atmospheres, if the temperature remains constant?
Answer:
is you'r question correctly?
or not
what is the volume of 0.284g of carbon dioxide at STP ??
Answer:
Explanatio
NCO2= 0, 248 /44= 0 ,005636
VCO2= 0,005636* 22,4= 0 ,126254545
2. 10.00 grams of a sample of hydrated PtCl4 are heated and lose 3.00 g of water. How many moles of water are combined with each mole of PtCl4?
Answer:
8 mol
Explanation:
Step 1: Calculate the mass of PtCl₄ in the sample
10.00 grams of a sample of hydrated PtCl₄ are heated and lose 3.00 g of water. The mass of PtCl₄ is:
mPtCl₄ = 10.00 g - 3.00 g = 7.00 g
Step 2: Calculate the moles corresponding to 7.00 g of PtCl₄ and 3.00 g of H₂O
The molar mass of PtCl₄ is 336.9 g/mol.
7.00 g × 1 mol/336.9 g = 0.0208 mol
The molar mass of H₂O is 18.02 g/mol.
3.00 g × 1 mol/18.02 g = 0.166 mol
The molar ratio of H₂O to PtCl₄ is:
0.166 mol H₂O/0.0208 mol PtCl₄ ≈ 8 mol H₂O/ 1 mol PtCl₄
What does a pH of 7 say about a solution?
O A. The solution is at equilibrium.
B. The solution is neutral.
O C. The solution is acidic.
O D. The solution is basic.
Answer:
Its's B
The Solution is neutral
Explanation:
Formation of HCl from H₂and Cl₂ is example of
photochemical
electrochemical
displacement
Answer:
Combination reaction.
Explanation:
The reaction depicted in the question is;
H2 (g) + Cl2 (g) ⟶ 2HCl (l)
Now, this reaction shows that two reactants namely hydrogen and chlorine react to form a single product named Hydrogen chloride. This process is called combination reaction.
Why does increasing the temperature make a solid dissolve faster?
- The solvent molecules bump into the solid more often.
- The solid is melted before mixing into the liquid.
- The chemical bonds of the solid are broken faster.
- The pressure of the solute on the solid is increased.
Answer:
The solvent molecules bump into the solid more often
Explanation:
Increasing the temperature makes a solid dissolve faster because the solvent molecules bump into the solid more often.
What happens when you increase the temperature of the solvent?If we heat the solvent, the average kinetic energies of its molecules increase. Hence, the solvent is able to dislodge more particles from the surface of the solute. Thus, increasing the temperature increases the solubilities of substances. For example, sugar and salt are more soluble in water at higher temperatures.
Does raising the temperature make a substance dissolve faster in a solvent?The temperature of the solvent is another factor that affects how fast a solute dissolves. Generally, a solute dissolves faster in a warmer solvent than it does in a cooler solvent because particles have more energy of movement.
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Name one diatomic compound which is mononuclei
Answer:
Common diatomic molecules include hydrogen (H2), nitrogen (N2), oxygen (O2), and carbon monoxide (CO). Seven elements exist as homonuclear diatomic molecules at room temperature: H2, N2, O2, F2, Cl2, Br2, and I2. The bond in a homonuclear diatomic molecule is non-polar due to the electronegativity difference of zero.
which state of matter expands most when heated
Answer:
Gases expand the most upon heating because the intermolecular space is more than in solids or liquids.
Explanation:
hopes it helps
