32. A sample of potassium is composed of 23% K-39, 48% K-40 and the remainder K-41. Calculate the average mass
of the sample.
Answer:
40.06 amu.
Explanation:
From the question given above, the following data were obtained:
Isotope A (K-39)
Mass of A = 39 amu
Abundance of A = 23%
Isotope B (K-40)
Mass of B = 40 amu
Abundance of B = 48%
Isotope C (K-41)
Mass of C = 41 amu
Abundance of C = 100 – (23 + 48)
Abundance of C = 100 – 71
Abundance of C = 29%
Average mass =?
Average mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
= [(39 × 23)/100] + [(40 × 48)/100] + [(41 × 29)/100]
= 8.97 + 19.2 + 11.89
= 40.06 amu
Thus, the average mass of potassium is 40.06 amu
How many grams of nitric acid, HNO3, are required to neutralize (completely react with) 4.30 g of Ca(OH)2?
Answer:
8.25 g HNO3 (please correct me if I'm wrong!)
The correct answer is 7.31 g HNO₃.
What is nitric acid used for?Nitric acid is used for the production of ammonium nitrate, a major component of fertilizers. It is also used for producing explosives like nitroglycerin and trinitrotoluene (TNT) and for oxidizing metals.
Please check the attached file for an explanation.
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What is the minimum temperature for hot water when using
heat to sanitize in a manual operation?
0 171°F
160°F
O 184°F
O 71°F
Answer:
171°F is the answer of this question
20 points to whoever can answer these 3 questions correctly
Answer:
1) A. NO
2) B. 4
3) D. 8
Explanation:
HOW CAN I DO AN EXPERIMENT WITH THIS THINGGGG I-
Answer:
omg i love grass hopperszszszs
Explanation:
you should give it a mate
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PLS HELP ME WITN THIS ILL GIVE BRAINLIEST
A chemical property of a substance is a certain characteristic that can only be observed by participating in a chemical reaction. Alternatively, a chemical property of a substance is something that can only be observed when the substance undergoes a chemical change.
I'm not sure what you're supposed to do with the first four boxes; all four are examples of chemical properties. Do you have to name the specific type of chemical property as given in the description? If so, the following would be my answers:
Flammability/Combustibility: The ability of a substance to burn.
The next two are quite strange; I'm not aware of a term that cleanly describes reactivity with water or acid. I suspect that, given the level of the material here, the general property of "reactivity" might be the answer for both the second and third descriptions
(Water-)reactivity: Some substances react when put in water.
(Acid-)reactivity: Some substances react when put in acid.
Light sensitivity: Light can interact with some things to form new substances.
As for the chart, I've filled it in as shown in the attached image. Please take care to double-check what I've written; in particular, when it comes to the property, I might have used a different term from what you were taught in class or provided in some other resource that I don't have access to. I've also color-coded qualitative/quantitative and physical/chemical for your convenience.
NH4NO3->N2O+2H2O How many grams of NH4NO3 are required to produce 33.0 games of N2O
Answer:
the moles of N2O are 33/(14.2 + 16) = 0,75 (mol)
NH4NO3 -----------> N2O + 2H2O
0.75 <--- 0.75
=> The moles of NH4NO3 are 0,75 mol
=> m = 0,75(14.2 + 4 + 16.3) = 60 (g)
Explanation:
Answer:
60 grams of NH4NO3
Explanation:
2222222c is right, but here's a better visualization of the answer!How many valence electrons does the following element have? 1s2 2s2 2p6 3s1
How many moles of hydrogen are produced from the reaction of 3.0 moles of zinc?
Answer:
3 moles
Explanation:
How many moles of potassium are needed to react completely with 7.50 mol of chromium (III) oxide? Show work.
Answer:
45 mol
Explanation:
First you need to balance the equation:
6K + Cr2O3 = 3K2O + 2Cr
the proportion of the coeficients of potassium and chromium oxide is 6 to 1 so we need to multiply 7.5 by 6 to get 45.
What happens in a single-replacement reaction?
A. One reactant breaks apart to form new compounds.
B. Two reactants combine to form one product.
C. Two reactants exchange elements with each other.
D. One reactant replaces an element in another reactant.
Answer:
D
Explanation:
A single-replacement reaction occurs when one element replace another in a single compound.
Which is a problem with using wind turbines to produce energy?
WA. Wind turbines are efficient only in certain areas.
A.
O C. Wind turbines produce a large amount of energy.
D. Wind turbines create a large amount of pollution.
B. Wind turbines occupy a small area of land.
Answer:
they are only efficient in certain areas
Explanation:
Wind turbine are efficient only in certain areas it is a problem with using wind turbines to produce energy.
What is Wind Turbine?Wind turbine convert the wind energy into the electricity. It is a power generating device that converts the kinetic energy in to electrical energy.
Now lets check all option one by one:
Option (A): Wind turbines are efficient only in certain areas it is a problem with using wind turbines to produce energy because the flow of air from areas of high pressure towards the lower pressure.
So, it is correct option.
Option (B): Wind turbines occupy a lot of space to work.
So, it is incorrect option.
Option (C): Wind turbines produce a large amount of energy is not a problem.
So, it is incorrect option.
Option (D): Wind turbines does not create a pollution or it does not pollute the air or water.
So, it is incorrect option.
Thus, we can say that Wind turbines are efficient only in certain areas it is a problem with using wind turbines to produce energy because the flow of air from areas of high pressure towards the lower pressure.
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How long is radioactive waste from nuclear plants radioactive?
a-100 years
b-10,000 years
c-100,000 years
d-1,000 years
Answer:about 10,000 years b maybe
Explanation:Strontium-90 and cesium-137 have half-lives of about 30 years (half the radioactivity will decay in 30 years). Plutonium-239 has a half-life of 24,000 years. High-level wastes are hazardous because they produce fatal radiation doses during short periods of direct exposure.
The radioactive waste from nuclear plants is radioactive for 10,000 years and the correct option is option B.
What is Radioactive waste?
The waste produced by a nuclear power plant or lab is referred to as radioactive waste. They include radioactive substances that are dangerous to the environment and the majority of biological forms. The wastes degrade over time.
Radioactive wastes are stored to-
allow some radioactive wastes to decay to nonradioactive wastes, reduce transport risks; provide lag storage between waste generator, treatment, and disposal sites; simplify disposal; and manage radioactive wastes until disposal facilities become available.Therefore, the radioactive waste from nuclear plants is radioactive for 10,000 years and the correct option is option B.
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How many atoms of aluminum (Al) are in 6.4 mol of aluminum
Answer:
How many atoms are in 6.2 moles of aluminum? I mol = 6.02X1023 atoms so 6.2 mol = 6.2x (6.02x1025) = 3.73 x1024 atoms of Aluminum
There are approximately 3.86528 × 10²⁴ atoms of aluminum (Al) in 6.4 mol of aluminum.
To determine the number of atoms of aluminum (Al) in 6.4 mol, we use Avogadro's number, which states that 1 mole of any substance contains 6.022 × 10²³ particles (atoms, molecules, or ions).
Given that 6.4 mol of aluminum is provided, we can use Avogadro's number to calculate the number of atoms:
Number of atoms = (6.4 mol) × (6.022 × 10²³ atoms/mol)
Calculating the multiplication, we find:
Number of atoms = 3.86528 × 10²⁴ atoms
Therefore, there are approximately 3.86528 × 10²⁴ atoms of aluminum (Al) in 6.4 mol of aluminum.
This calculation is based on the fact that 1 mole of aluminum contains Avogadro's number of aluminum atoms. The molar quantity allows us to convert between the mass of a substance and the number of atoms or molecules present.
Avogadro's number is a fundamental constant in chemistry that relates the mass of a substance to the number of particles it contains. It is approximately 6.022 × 10²³ particles per mole. By using this conversion factor, we can determine the number of atoms present in a given amount of substance.
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Does the physical form of the material matter for mass-mole
and mole-mass calculations?
The physical form of the material matter for mass-mole and mole-mass calculations is solid.
What is the relation between mass & moles?Relation between mass and moles will be represented as:
n = W/M, where
W = given mass in grams
M = molar mass in grams/mole
So the physical state of the matter that is used in the above relation is solid because solid is only present in the grams and kilogrmas quantity.
Hence solid is the physical form of the matter.
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How many significant figures are in the number 020.310
Answer:
5
Explanation:
Sorry, don't have one
Hope this helps and I get brainliest <3
Shape of a molecule having four Bond pairs and two lone pair of electron will be
Answer:
bipetal
Explanation:
this is because 2 electrons will be donated by each element, as seen in NO2
Which is true of multicellular organisms?
A. Their cells lack a nucleus.
B. Their cells are eukaryotic.
C. They have no fertilized eggs.
.
Write a net ionic equation for the neutralization reaction of acid with a hydroxide base. (Include phase symbols)
Answer:
salt + water. It is called the ionic equation for neutralisation. the acid to form a salt solution.
Explanation:
So what you end up with is you always end up H+ plus OH- yields H2O, because HCl, and NaOH, since they're strong, they fully dissociate. So the Na+, and the Cl - are spectator ions. So with a strong acid and strong base, the net ion equation is always H+ plus OH- yields H2O.
Changes in thermal energy provide evidence that a chemical reaction
has occurred. Which of the following BEST describes a chemical reaction
in which energy is released?
Select one:
Exothermic reaction.
Reversible reaction
Physical reaction
Endothermic reaction.
Answer:
Exothermic reaction
Explanation:
Exothermic reaction is a reaction in which energy is evolved from the reaction to the surroundings
Pls help me if your good at science I’ll mark brainliest <3
Answer:
C. Intrusive ignesious
An example of a binary compound is
a.
potassium chloride
b.
ammonium chloride
potassium chlorate
ammonium chlorate
Answer:
a. KCl
Explanation:
a. KCl - made of 2 elements
b. NH4Cl
c. KClO3
d. NH4ClO3
What is Haber's process? Write it with chemical reaction.
Answer: Habers process is the industrial process used for the production of ammonia
[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]
Explanation:
Habers process is the industrial process used for the production of ammonia. It uses hydrogen from natural gas and nitrogen mainly from atmosphere under extremely high pressures (150-200atm) and moderately high temperatures [tex](400-450^0C)[/tex].
The catalyst used in Habers process is iron.
The balanced chemical reaction is:
[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]
Which of these have a double bond? Pick all that apply:
SiCL2Br2
H2O
HBr
SeBr2
CO2
Answer: Here goes ur answer
CO2
Explanation:
A 5.0 balloon containing nitrogen gas is cooled from 25 degrees to 5°C. What is the final volume of the balloon?
Answer:
5.4
Explanation:
V1=5.0
T1=25+ 273=298
V2= z(unknown)
T2=5+273=278
V1/T1 =V2/T2
V2=V1T2/T1
=5*298/278
=5.4
If N and O were to bond, the difference in electronegativity would be
and we would expect the bond to be
ionic, covalent)
Answer:
The bonds between nitrogen and oxygen are covalent bonds made from sharing electron pairs. The electronegativity of oxygen is 3.5.
In your own words, write a definition for the term periodic.
Answer: The definition of periodic is something that is recurring at regular intervals, or happens from time to time. An example of periodic is a person's birthday happening once each year.
hope this helps y❣️
how many atoms are there in 6.4 moles of H2?
Answer:
7.71 ×10²⁴ atoms (3 s.f.)
Explanation:
Please see the attached picture for the full solution.
☆ or number of atoms, or fundamental units
(this is sometimes written as number of particles)
Further explanantion:
(☆:) Here, we are looking at the number molecules since H₂ is a molecule.
1 mole of a substance is the amount of substance which contains the same number of particles. Thus, when using Avogadro's Constant, the units that we are looking at follows the units of the question. Then, look at what the question is asking for and answer accordingly.
The 2nd picture shows an example of another molecule, H₂O.
Some other examples would be:
1 mole of Na (an atom) --- 6.022 ×10²³ atoms
1 mole of CO₂ (a molecule) --- 6.022 ×10²³ molecules
1 mole of Na+ --- 6.022 ×10²³ ions
Thus, if we look at the 2nd image again, we can say that 1 mole of H₂O contains 6.022 ×10²³ molecules since H₂O is a molecule. However, if the question is asking for the number of atoms, it is not right to say that there are 6.022 ×10²³ atoms. Instead, there are 1.2044 ×10²⁴ H atoms and 6.022 ×10²³ O atoms, giving us a total of 1.8066 ×10²⁴ atoms in 1 mole of H₂O.
10. Un volumen de 1.0 mL de agua de mar contiene casi 4.0 3 10212 g de Au. El volumen total de agua en los océanos es de 1.5 X 1021 L. Calcule la cantidad total de Au (en gramos) existente en el agua de mar y su valor total en dólares (Suponga que el oro tiene un precio de 948 dólares por onza)
Answer:
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Explanation:
