Answer:
14500.
Explanation:
1) Avlgadro's number is 6.022*10²³;
2) 1 mol is 6.022*10²³ atoms of Hellium, then 8.7*10²⁷ atoms is
[tex]3) \ \frac{87*10^{26}}{6*10^{23}}=14.5*10^3=14500[moles].[/tex]
Gold ions, Au*(aq), can easily be made to precipitate out of a solution as gold metal. Simply
bring another metal into the solution, and this metal becomes the reducing agent in the
chemical change. Write the half-reaction to represent the change in gold as it precipitates out
of the solution.
Don’t need answer unless you want to solve:) I just need help with understanding the explanation
Explanation:
gold is found very low down in the reactivity series thus is relatively unreactive. Metals found above gold in the series are more reactive compared to gold and thus is able to undergo a single displacement reaction, replacing gold in solution, which is then precipitated as a solid.
Nitrogen gas (N2) will bond with hydrogen gas (H2) to form ammonia (NH3), a common compound in living organisms. This reaction involves two reactants forming a single product. What type of reaction is this?
*
2 points
a) combination
b) single replacement
c) decomposition
d) neutralization
Answer:
c could someone try to do the page for me please i will really appreciate it I'll mark brainliest i need it by the end of my geometry class
Answer: The correct answer is (a)combination.
Explanation: Direct combination and synthesis are the same process in which two reactants form to make a product
CHEMISTRY HELP!! PLS DON'T ANSWER IF YOU DON'T KNOW THE ANSWER. I WILL MARK BRAINLIEST IF YOU DO KNOW!! :D
1. How many molecules of manganese are there in 1.75 moles? There are 6.02 x10^23 molecules/mol
A. 59.94 molecules
B. 1.75 x10^23 molecules
C. 10.5 x10^23 molecules
D. 6.03 x 10^23 molecules
2. The molar mass of AlCl3 is 133.34 g/mol. How many molecules of AlCl3 are there in 2 g?
A. 2.05 x 10^21 molecules
B. 4.01 x 10^25 molecules
C. 9.04 x 10^21 molecules
D. 11.1 x 10^25 molecules
3. What is the mass of hydrogen atoms that is measured at 54 u? The relationship between atomic mass units (u) and grams (g) is 1 u = 1.66 x 10^-24 g.
A. 54 x 10^-24 g
B. 62.25 x10^-24 g
C. 74.64 x10^-23 g
D. 89.64 x10^-24 g
Answer:
1. C. [tex]10.5 *10^{23[/tex] molecules
2. C. [tex]9.04*10^{21}[/tex] molecules
3. D. [tex]89.64*10^{-24[/tex] g
Explanation:
1. To find the molecules of manganese from moles use this equation:
[tex]moles (x)*\frac{6.022 *10^{23} molecules }{1 mole}[/tex]
Insert the amount of moles given (1.75) into the equation and solve:
[tex]1.75moles*\frac{6.022 *10^{23} molecules }{1 mole}[/tex] = [tex]1.05 *10^{24[/tex] molecules.
In the question they have the answer as [tex]10.5 *10^{23[/tex] which is the same as [tex]1.05 *10^{24[/tex]. So, [tex]10.5 *10^{23[/tex] is the answer.
2. To find molecules from grams per mole, use this equation:
[tex]x grams *\frac{1 mol}{mass(g)} *\frac{6.022*10^{23} molecules}{1 mol}[/tex]
The molar mass of AlCl3 is 133.34 g/mol, and we want to know how many molecules in 2 grams. Plug these into the equation.
[tex]2 g *\frac{1 mol}{133.34g} *\frac{6.022*10^{23} molecules}{1 mol}[/tex] = [tex]9.04*10^{21}[/tex] molecules
The answer will be C. [tex]9.04*10^{21}[/tex] molecules.
3. To find the mass of the hydrogen atoms, use this equation:
[tex]x u*\frac{1.66*10^{-24}g}{1u}[/tex]
We are given 54 u. Plug this into the equation and solve:
[tex]54 u*\frac{1.66*10^{-24}g}{1u} = 8.964*10^{-23[/tex] grams
Once again, the question gives us this answer in a different form of [tex]89.64*10^{-24[/tex] g, but they are the same. So, the final answer is D. [tex]89.64*10^{-24[/tex] g.
I hope this helps! If you have any questions about my work feel free to leave them in the comments!
Please answer ASAP on a timed exam
How much heat is required to convert 90. g of ice at -4.0 C to water vapor (steam) at 110 C
Answer: How much heat is required to convert 29 g of ice at -4.0 ˚C to water vapor at 105 ˚C (report your answer to three significant figures)? Answer all five parts, showing your detailed calculations: i) Heat to warm ice from -4.0 to 0 oC: ii) Heat to convert ice to liquid: iii) Heat to warm liquid to boiling: iv) Heat to convert liquid to gas
Explanation:
e
A casein isolation experiment yields 0.2g from 10g of milk What is the percentage of casein in the milk?
Answer:
2%
Explanation:
.2 g / 10 g * 100% = 2%
Does the NaOH test for calcium ions work when NaOH is added to limewater?
Answer:
Calcium hydroxide is a white precipitate, too, and it won't dissolve if more sodium hydroxide is added to the solution. No significant precipitate will be formed between calcium ions and ammonia.
URGENT!!!
pH of a solution that has a [H3O+] = 6.25 x 10-5 M
The required pH of the solution is 4.2 which means solution is acidic in nature.
How do we calculate the pH?pH of the solution is define as the negative logarithm of the concentration of the hydronium ion, and it is represented as:
pH = -log[H⁺]
Given concentration of H₃O⁺ ion = 6.25×10⁻⁵ M
On putting this value on above equation, we get
pH = -log(6.25×10⁻⁵) = 4.2
Hence required pH of the solution is 4.2.
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The hypothesis stated that the fraction of nuclei still radioactive after n half-life cycles should be 0.5n. How well does the regression equation support the hypothesis?
The regression equation supports the hypothesis by showing associations between sets of scientific data (in this case, half life cycle and radioactivity).
What is the regression equation?The regression equation is a type of mathematical tool employed to determine the association between variables.
The regression equation can help to understand the relationships between independent and dependent variables.
In conclusion, the regression equation supports the hypothesis by showing associations between sets of scientific data.
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Answer:
Quite Strongly
Explanation:
Got it right 2022 edge
which pair of elements would form metallic bonds in a compound
Answer: Chlorine & Bromine
Explanation:
QUESTION 10
_________________________________ is the major regulatory enzyme in glycolysis that catalyzes the irreversible phosphoryl transfer from ATP to fructose 6-phosphate.
A.
Enolase
B.
Phosphofructokinase-1
C.
3-phosphoglycerate kinase
D.
Aldolase
Answer:
B
Explanation:
Phosphofructokinase-1
what property of water molecules is responsible for its high surface tension
Answer:
Hydrogen bonding
Explanation:
A student is investigating how a bowl of ice changes in one hour. She places a bowl of ice on a table inside her classroom. She observes it at three different times. The diagram shows her observations.
The diagram shows a bowl with ice at 1:00 P M, 1:30 P M, and 2:00 P M. At 1:00 P M, the bowl is filled with ice cubes. At 1:30 P M, some ice cubes remain and they are floating in some water. At 2:00 P M, the bowl is filled only with water.
Question
Which question is the student ,begin emphasis,most,end emphasis, likely trying to answer?
Answer options with 4 options
A.
How does water evaporate?
B.
How can the water cycle be modeled?
C.
How is water chemically changed by melting?
D.
How does temperature affect the physical state of water?
The student, begins emphasis, most, ends emphasis, likely trying to answer How does temperature affect the physical state of water.
What is a physical change?A usually reversible change in the physical properties of a substance, like size or shape: Freezing a liquid is a physical change.
The temperature has a direct effect on whether a substance exists as a solid, liquid or gas. Generally, increasing the temperature turns solids into liquids and liquids into gases; reducing it turns gases into liquids and liquids into solids.
Hence, option D is correct.
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A 15 mL sample of water from the lemur exhibit required 1.58 mL of a sulfuric acid titrant to reacht he endpoint. Calculate the alkalinity of the exhibit in mg/L of CaCO3 if the titrant conentration was 0.019 M. The molecular weight of calcium carbonate is 100.0869 g/mol.
CaCO3(aq) + H2SO4(aq) --> CaSO4(aq) + H2O(l) + CO2(g)
Based on the mole ratio of the reaction, the alkalinity of the exhibit is 0.02 mg/L of CaCO3.
What is alkalinity?Alkalinity is a measure of the hydroxide ion concentration of a solution.
From the equation of the reaction, the mole ratio is 1 :1.
1 mole of the sample reacts with 1 mole of acid.
Moles of titrant = 1.58 mL × 0.019 M = 0.003 mmoles
Moles of samples = 0.003 mmoles
The concentration of sample = 0.003 mmol/15 mL = 0.0002 M
Mass concentration = molar concentration × molarmass concentration = 0.0002 M × 100.0869 g/mol
mass concentration = 0.02 g/mL
Converting to mg/L:
0.02 g/mL × 1000 mg/1000 L = 0.02 mg/L
Therefore, the alkalinity of the exhibit is 0.02 mg/L of CaCO3.
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The intermolecular forces that exist between the molecules of H₂O is...
Answer: hydrogen bonding
Explanation:
When hydrogen atoms bond with oxygen atoms, there is hydrogen bonding.
Can someone help me with my homework, and show step by step so I can learn?
Answer:
Not sure.
Explanation:
Give me some time.
***After 42 days, 2 g of phosphorus-32 has decayed to 0.25 g. What is the half-life of phosphorus-322
The answer is the half life of phosphorus-32 is of 14 days .
What is Half Life ?
The half-life of a radioactive isotope is the amount of time it takes for one-half of the radioactive isotope to decay.
The half-life of a specific radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope.
Mass of atoms initially,
N₀ =2.0 g
Mass after 42 days,
N =0.25 g
mass left undecayed we have,
[tex]\rm\dfrac{N}{N_{0}} = \dfrac{1}{2^{n}}[/tex]
where n is number of half lives occured (the number of times it disintegrated into half of original)
[tex]\rm\dfrac{0.25}{2} = \dfrac{1}{2^{n}}[/tex]
[tex]\rm\dfrac{1}{8} = \dfrac{1}{2^{n}}[/tex]
[tex]\rm\dfrac{1}{2^{3}} = \dfrac{1}{2^{n}}[/tex]
n= 3
number of half lives occured in 42 days is 3
if half life is [tex]\rm t_{\frac{1}{2} }[/tex]
then
3* ( [tex]\rm t_{\frac{1}{2} }[/tex] ) = 42
[tex]\rm t_{\frac{1}{2} }[/tex] = 14 days
Therfore the half life of phosphorus-32 is of 14 days .
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ANSWER THIS CORRECTLY FOR BRAINLIEST!!!
short fur
Explanation:
According to Mendel's Law of Dominance, if short fur is the dominant trait, and long fur is recessive; a heterozygous genotype will definitely be phenotypically short fur.
[tex]\huge\mathfrak\colorbox{white}{}[/tex]
MarkThe BrainliestBecause you'll definitely get it right.
If a solution has 17.2 moles of LiF in 2000 mL of water, what is the molarity?
4.2 M
10 M
2 M
8.6 M
Molarity, M = (n x 1000) / vol (in ml)
M = 17.2 x 1000/ 2000
M = 8.6 mol/L
how was oil made and who created it
Answer:
About 300 million years ago,
Explanation:
Col. Edwin Drake
Answer:
Oil was formed from the animals and plants that lived millions of years ago and the creator is John D Rockefeller and others in 1870
in the following reaction 10.5 moles of chromium are added to 6.8 moles of oxygen find limiting an excess reactants and answer the questions that follow.
Answer:
If 3.4 moles of carbon dioxide (CO2) form at the end of the reaction, 1.7 moles of oxygen gas
(02) and 3.4 moles of carbon monoxide (CO) entered the reaction
Explanation:
The rule of three or is a way of solving problems of proportionality between three known
values and an unknown value, establishing a relationship of proportionality between all of
them. That is, what is intended with it is to find the fourth term of a proportion knowing the
other three. Remember that proportionality is a constant relationship or ratio between different
magnitudes.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so
does the other (or when one magnitude decreases, so does the other), the direct rule of three
must be applied. To solve a direct rule of three, the following formula must be followed:
ab
cx
So
C*b
T =
a
In this case, it is possible to use the reaction stoichiometry of the reaction (that is, the
relationship between the amount of reagents and products in a chemical reaction) and the rule
of three to calculate the quantities of moles requested:
.
,
If by stoichiometry 2 moles of CO2 are formed by 1 mol of O2, if 3.4 moles of CO2 are
formed, how many moles of O2 are needed?
molesofo2 = 3.42
=
moles of O2=1.7 moles
• If by stoichiometry 2 moles of CO2 are formed by 2 moles of CO, if 3.4 moles of CO2 are
formed, how many moles of CO are needed?
molesof CO =
=
3.4*2
2
moles of CO=3.4
How many moles of water would be used reacting with 500g of P4010? *
P20,0 + H2O → H, PO,
PO
4
4 10
Answer:
410
Explanation:
:)))))))))))))))))))))))))))))))
Ba(OH)2 (aq) + HNO3(aq) + Ba(NO3)2(aq) + H2O(1)
Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer:
This will be really short but pi2 is the condense amount that (425h209) will equal 4.98288493
Explanation:
Question 12 of 32
Which element has 5 valence electrons?
The Periodic Table
O A. Magnesium (Mg)
O B. Rubidium (RD)
O C. Arsenic (As)
O D. Boron (B)
Answer: Arsenic
Explanation:
Arsenic is in column 15 of the periodic table, which means that it has 5 valence electrons.
if 20.1 g of KBr (MM=119.00 g/mol) are added to a 500.0 mL volumetric flask and water is added to fill the flask what is the concentration of KBr in the resulting solution
The concentration of KBr in the resultion solution is 0.34 M
StoichiometryFrom the question, we are to determine the concentration of KBr in the resulting solution
First, we will determine the number of mole of KBr present
Using the formula,
[tex]Number\ of\ moles = \frac{Mass}{molar\ mass}[/tex]
Mass of KBr = 20.1 g
Molar mass of KBr = 119.00 g/mol
∴ Number of moles of KBr present = [tex]\frac{20.1}{119.00}[/tex]
Number of moles of KBr present = 0.1689 mole
Now, for the concentration of the KBr
Using the formula,
[tex]Concentration = \frac{Number\ of\ moles}{Volume}[/tex]
Volume of solution = 500.0 mL = 0.50 L
∴ Concentration of KBr = [tex]\frac{0.1689}{0.50}[/tex]
Concentration of KBr = 0.3378 M
Concentration of KBr ≅ 0.34 M
Hence, the concentration of KBr in the resultion solution is 0.34 M
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The substance that dissolves the solute
A) Solubility
B) Solvent
C) Solute
Answer:
B) Solvent
Explanation:
The substance being dissolved is called the solute and the liquid doing the dissolving is called the solvent. In order for a substance to dissolve, the molecules of the solute need to interact with the molecules of the solvent.
Convert 27 calories into kcal.
27
[tex]27 ~\text{cal} = \dfrac{27}{1000} ~ \text{kcal} = 0.027~ \text{kcal.}[/tex]
a scientist prepares a solution by dissolving 25.22g of lithium fluoride (lif) in 2.2 liters of water. What would be the molarity of the solution?
Answer:
[tex]c = 0.441mol{dm}^{ - 1} [/tex]
Explanation:
[tex]m = 25.22g \\ v = 2.2l = 2.2 {cm}^{3} \\ mm(lif ) = 7 + 19 \\ = 26g {mol}^{ - 1} \\ number \: of \: moles(n) = \frac{m}{mm} \\ = \frac{25.22g}{26g {mol}^{ - 1} } \\ = 0.97mol \\ concetration(c) = \frac{n}{v} \\ = \frac{0.97mol}{2.2 {cm}^{3} } \\ c = 0.441mol {dm}^{ - 3} [/tex]
A radioactive isotope has a half-life of 3.0 hours. If a scientist has 30 grams of the isotope, how much is left after 15 hours?
Answer:
0.9375
Explanation:
3.0x30x15 = 17 496 000 kg [tex]sx^{2}[/tex]
subtract or divde
then you take the 9 and 375 add 0.9000 and combine them and there you go.
[tex]+\frac{0.9000}{375} =0.9375[/tex]
The periodic table is important"
Give three(3) reasons to support this statement?
Periodic table is important because it provides information, make easier to study and know about relationship between elements.
Why periodic table is important?The periodic table is very important because it provides a huge amount of information about elements and their relationship to one another. The table can be used to know about the properties of elements.
So we can conclude that periodic table is important because it provides information, make easier to study and know about relationship between elements.
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