Answer:
~69.744 moles of Ca
Explanation:
Using Avogadro's constant , we know that:
1 mole = 6.022 x 10^23 atoms
S0, the number of moles in 4.20 x 10^25 atoms of Ca:
=(4.20 x 10^25 x 1 )/(6.022 x 10^23)
~69.744 moles of Ca
Q2:How many atoms are in 0.35 moles of oxygen?
1 mole = 6.022 x 10^23 atoms
S0, the number of atoms in 0.35 moles of oxygen:
=[0.35 x (6.022 x 10^23)]
=2.1077 x 10^23 atoms of Oxygen
Hope it helps:)
Which of these is NOT a producer in the coral reef ecosystem? *
1. phytoplankton
2. sea grass
3. microalgae
4. coral
Answer:
option number 4. 'coral'
Explanation:
-
I dont understand this
Answer:
me too
Explanation:
Pick the correct statement about the pure water. Group of answer choices Pure water contains no ions. Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O ] ions. Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O ] ions. Pure water is an electrolyte. Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions.
Answer:
Pure water contains no ions. TRUE
Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions. TRUE
Explanation:
This is the equilibrium for pure water:
2H₂O ⇄ H₃O⁺ + OH⁻ Kw
We see that pure water has no Ions. Pure water can not conduct electricity.
Generally ionized water comes from the water tap.
Another feature of pure water is pH.
Definetely pH of pure water is : 7
As pH = 7, [H₃O⁺] = 1×10⁻⁷
Then, [OH⁻] = 1×10⁻⁷
This is reazonable because Kw is 1×10⁻¹⁴ and Kw = [H₃O⁺] . [OH⁻]
In conclussion:
Pure water contains no ions. TRUE
Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions. TRUE
Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O+] ions. FALSE
Pure water is an electrolyte. FALSE
Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions. FALSE
8. What was the original concentration in the BHL sample, if the dilution is 1:500 and the concentration 0.07 mg/ml
Answer:
The original concentration is "35 mg/ml".
Explanation:
According to the question,
The solution is diluted,
= 1:50
The initial volume,
V1 = 1 ml
Final concentration,
= 0.07 mg
then,
The final volume,
V2 = 500 ml
As we know,
⇒ [tex]V_1N_1=V_2N_2[/tex]
or,
⇒ [tex]N_1=\frac{V_2N_2}{V_1}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{500\times 0.07}{1}[/tex]
⇒ [tex]=\frac{35}{1}[/tex]
⇒ [tex]=35 \ mg/ml[/tex]
A 0.07 mg/mL BHL solution was prepared by performing a 1:500 dilution on a 35 mg/mL solution.
A 1:500 dilution was carried out to prepare a 0.07 mg/mL BHL solution. We can find the concentration of the initial solution using the dilution rule.
What is the dilution rule?It is an equation that relates the concentration and volume of a concentrated and a dilute solution. The mathematical expression is:
C₁ × V₁ = C₂ × V₂
where,
C₁ is the concentration of the concentrated solution.V₁ is the volume of the concentrated solution.C₂ is the concentration of the dilute solution.V₂ is the volume of the dilute solution.C₁ = C₂ × (V₂/V₁)
C₁ = 0.07 mg/mL × (500/1) = 35 mg/mL
A 0.07 mg/mL BHL solution was prepared by performing a 1:500 dilution on a 35 mg/mL solution.
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When an acid reacts with a strong base which product always forms
Answer:طيزي
Explanation:
Silver nitrate, AgNO3, reacts with ferric chloride, FeCl3, to give silver chloride, AgCl, and ferric nitrate, Fe(NO3)3. In a particular experiment, it was planned to mix a solution containing 25.0 g of AgNO3 with another solution containing 45.0 grams of FeCl3. Write the chemical equation for the reaction.
Answer:
[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]
Explanation:
From the given question,
The chemical equation is:
[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]
We are given that:
mass of [tex]FeCl_3[/tex] = 45 g
number of moles of [tex]FeCl_3[/tex] = 45 g/162.2 g/mol
= 0.28 mol
mass of [tex]AgNO_3[/tex] = 25g
number of moles of [tex]AgNO_3[/tex] = 25/169.87
= 0.147 mol
From the given equation 1 mole of [tex]FeCl_3[/tex] is required to make 3 mole of [tex]AgNO_3[/tex]
0.28 mole of [tex]FeCl_3[/tex] = 0.28 × 3 = 0.84 mol of [tex]AgNO_3[/tex]
Here [tex]AgNO_3[/tex] is the limiting reagent.
Thus,
3 mole of [tex]AgNO_3[/tex] = 3 moles of AgCl
0.147 mole of [tex]AgNO_3[/tex] = 0.147 mole of AgCl produced.
Now we need to find the amount of NF3 that can be formed by the complete reactions of each of the reactants. If all of the N2 was used up in the reaction, how many moles of NF3 would be produced
The question is incomplete, the complete question is:
Nitrogen and fluorine react to form nitrogen fluoride according to the chemical equation:
[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]
A sample contains 19.3 g of [tex]N_2[/tex] is reacted with 19.3 g of [tex]F_2[/tex]. Now we need to find the amount of [tex]NF_3[/tex] that can be formed by the complete reactions of each of the reactants.
If all of the [tex]N_2[/tex] was used up in the reaction, how many moles of [tex]NF_3[/tex] would be produced?
Answer: 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
In the given chemical reaction, [tex]N_2[/tex] is considered as a limiting reagent because it limits the formation of the product and it was completely consumed in the reaction.
We are given:
Mass of [tex]N_2[/tex] = 19.3 g
Molar mass of [tex]N_2[/tex] = 28.02 g/mol
Putting values in equation 1:
[tex]\text{Moles of }N_2=\frac{19.3g}{28.02g/mol}=0.689mol[/tex]
For the given chemical reaction:
[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]
By the stoichiometry of the reaction:
1 mole of [tex]N_2[/tex] produces 2 moles of [tex]NF_3[/tex]
So, 0.689 moles of [tex]N_2[/tex] will produce = [tex]\frac{2}{1}\times 0.689=1.378mol[/tex] of [tex]NF_3[/tex]
Hence, 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.
if you were conducting an experiment with pepsin which has an optimal enzymatic actigity at ph 2.3, wat buffer would be the best choice
Answer: One with a pKa of 1.9
Hope this helps <3
P.S Fun Fact~~
There are only two words in the English language that have all five vowels in order: "abstemious" and "facetious."!
Answer:
Explanation: Is there choises? H3PO4 / NaH2PO4 buffer with equal concentrations would form a buffer solution pH = 2.15
7. In science, the process/thing that you examine/focus on is called the ??
and anything outside of this focus is called the ??
Answer:
Subject of the experiment and out of scope
Explanation:
In any research study, the process of thing studied is basically the subject of the experiment on which research is conducted to determine the outcomes. If any thing lies out of the experimental process reach, then it is said to be out of scope of the experiment.
If atoms are electrically neutral then how do they form bonds?
Answer:
The nucleus contains neutrons and protons; protons carry the positive charge. The shells contain electrons which carry the negative charge. So, how can the atom be changed. ... Covalent bonds are electrically neutral because they are not formed due to the transfer of electrons but sharing of electrons.Explanation:
Hope it helps ^-^
#CarryOnLearning
Answer:
When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral. ... Chemically, we say that the atoms have formed bonds
Calculate the volume of 0.07216 M AgNO3 needed to react exactly with 0.3572 g of pure Na2CO3 to produce solid Ag2CO3.
Answer:
93.4 mL
Explanation:
Let's state the reaction:
2AgNO₃ + Na₂CO₃ → Ag₂CO₃ + 2NaNO₃
We determine the moles of sodium carbonate:
0.3572 g . 1mol / 105.98g = 3.37×10⁻³ moles
Ratio is 1:2. We say:
1 mol of sodium carbonate react to 2 moles of silver nitrate
Then, our 3.37×10⁻³ moles of carbonate may react to: 3.37×10⁻³ . 2
= 6.74×10⁻³ moles
If we convert to mmoles → 6.74×10⁻³ mol . 1000 mmol / mol = 6.74 mmol
Molarity is mol/L but we can use mmol /mL
6.74 mol / volume in mL = 0.07216 M
6.74 mol / 0.07216 M = volume in mL → 93.4 mL
solution of alcohol and water
[tex]\huge\mathsf{\red{\underline{\underline{Answer}}}}[/tex]
[tex]{\green{\dashrightarrow}}[/tex]When you mix the rubbing alcohol with water, the latter's molecules make hydrogen bonds with the water molecules. The alcohol dissolves in the water to form a homogenous solution, so you cannot distinguish the alcohol and the water anymore.
WILL GIVE BRAINLIEST TO FIRST ANSWER
picture ⬆️
Answer: A Molecular Approach, 2/e. Mole ratio. 2 mol C4H10 : 13 mol O2 : 8 mol CO2 : 10 mol H2O. ❖ 2 molecules of C4H10 react ... of aluminum and 73.15 g of sulfur are combined to form aluminum sulfide according to the equation:.
Explanation:
5.
When 0.421 g of BaCl2:2H20 and 0.722g of Na3PO4.12H2O mix with water
forming 500 mL of solution, how many grams of Ba3(PO4)2 precipitate?
Explanation:
2H2O and 0.722g of Na3PO4.12H20 mix with water forming 500 mL of solution, how many grams of Ba3(. ... Forming 500 ML Of Solution, How Many Grams Of Ba3(PO4)2 Precipitate?
When 0.421 g of BaCl₂ · 2 H2O and 0.722g of Na₃PO₄ · 12 H₂O mix with water forming 500 mL of solution then 0.003 mol/L of Ba₃(PO4)₂ precipitate.
What is Stoichiometry ?Stoichiometry is an important concept which helps us use the balanced chemical equation to measures the amount of reactants and products.
What is Molarity ?Molarity of solution is the number of moles of solute per liter of solution. Molarity is also called Molar Concentration.
Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]
How to find the number of moles ?Number of moles = [tex]\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
First we have to write the balanced chemical equation
2Na₃PO₄ · 12 H₂O + 3BaCl₂ · 2 H2O → Ba₃(PO4)₂ + 6 NaCl + 30 H₂O
Here 3 moles of BaCl₂ · 2 H2O produce 1 mole of Ba₃(PO4)₂
So,
Number of moles of BaCl₂ · 2 H2O = [tex]\frac{\text{Mass of}\ BaCl_2 . 2H_2O}{\text{Molar mass of}\ BaCl_2. 2H_2O}[/tex]
= [tex]\frac{0.421}{244.26}[/tex]
= 0.017
Number of moles of 2Na₃PO₄ · 12 H₂O = [tex]\frac{\text{Mass of}\ Na_3PO_4. 12H_2O}{\text{Molar mass of}\ Na_3PO_4 . 12H_2O}[/tex]
= [tex]\frac{0.722}{380.12}[/tex]
= 0.002
Therefore, Na₃PO₄ · 12 H₂O is the limiting reagent.
Now, put the value in above formula to find the molarity
Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]
= [tex]\frac{0.0017}{0.5}[/tex]
= 0.003 mol/L
Thus, from above conclusion we can say that 0.003 mol/L of Ba₃(PO4)₂ precipitate.
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explain the trend in boling point of alcohols in their homologous series
Explanation:
The boiling point of alcohols also increase as the length of hydrocarbon chain increases
The boiling point of alcohols also increase as the length of hydrocarbon chain increases.
Why boiling points of alcohols increases as the length of hydrocarbon chain increasesSince, boiling point depends upon type of bonds present in the molecules.If molecules have hydrogen bonding then boiling point is higher than others because hydrogen bond is stronger bond.So, higher energy or temperature required to break these bond or overcomes the inter molecular force of attraction.Since, alcohol contains hydrogen bonding. So, its boiling points are higher as compare to other compounds.Since, boiling points is also directly proportional to molar mass of molecules. So, molecule have higher molar mass has comparatively high boiling point.Example: An alcohols with lower hydrocarbon chain has lower boiling points as compare to alcohols with higher hydrocarbon chain.To learn more about alcohols,
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Given 32.0 g of water, if we see a temperature change from 25.0°C to 20.0°C, then how much heat energy (q) is transferred from the water?
(The specific heat of water is 4.184 J/g°C )
Answer:
Q = 669.44 J
Explanation:
Given that,
Mass of water, m = 32 g
The temperature change from 25.0°C to 20.0°C.
We need to find the amount of heat energy transferred. Let it is Q. We know that,
[tex]Q=mc\Delta T[/tex]
Where
c is the specific heat of water
Put all the values,
[tex]Q=32\times 4.184 \times (20-25)\\Q=669.44\ J[/tex]
So, 669.44 J of heat energy is transferred from the water.
(1 point) Which compound produces the greatest number of ions when one mole of it is dissolved in water
The question is incomplete, the complete question is;
Which produces the greatest number of ions when one mole dissolves in water? a. NaCl b. NH4Cl c. NH4NO3 d. Na2SO4
Answer:
Na2SO4
Explanation:
If we consider the compounds listed in the options one after the other;
NaCl produces two moles of ions in solution
NH4Cl produces two moles of ions in solution
NH4NO3 produces two moles of ions in solution
Na2SO4 produces three moles of ions in solution
We can see that Na2SO4 produces the greatest number of ions when one mole of the substance is dissolved in water, hence the answer above.
Can someone help me with a bio organic questions??♀️
Hydration of alkynes gives good yields of single compounds only with symmetrical or terminal alkynes. Draw the major organic product(s) formed when 3-methylcyclodecyne undergoes hydration in the presence of HgSO4 and H2SO4.
Answer:
Following are the solution to the given choice:
Explanation:
Hex-2-yne is just not alkyne symmetric, therefore two things respectively hexan-3-one and hexan-2-one are to be given.
The attached file it displayed the response along with the mechanism, please find the.
hello HELP ME pLS ANYONE with this question I will give u 18 points pls I need real help here:((
Answer:
Boiling - The process of a liquid changing to gas.
Boiling point - The temperature at which a liquid boils.
Condensing - The process of a gas changing to a liquid.
Distillate - The liquid collect from the condenser.
Residue - The liquid left behind in the distillation flask.
Vapour - Another name for gas.
Hope it helps :)
Which piece of glassware shown below is used to hold and dispense a solution of known concentration during a titration?
Answer:
Answer C
Explanation:
Got it off of q**zlet ;)
Answer
Its C confirmed
Explanation:
Just did the test
Given the reaction: N2 + O2 = 2NO for which the Keq at 2273 K is 1.2 x 10-4
a. Write the equilibrium constant expression for the reaction.
b. Write the equation that would allow you solve for the concentration of NO.
c. What is the concentration of NO if [NZ] = 0.166M and [02] = 0.145M?
Answer:
(a): The expression of equilibrium constant is [tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]
(b): The equation to solve the concentration of NO is [tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex]
(c): The concentration of NO is 0.0017 M.
Explanation:
The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]
(a):
The given chemical equation follows:
[tex]N_2+O_2\rightarrow 2NO[/tex]
The expression for equilbrium constant will be:
[tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]
(b):
The equation to solve the concentration of NO follows:
[tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex] ......(1)
(c):
Given values:
[tex]K_{eq}=1.2\times 10^{-4}[/tex]
[tex][N_2]_{eq}=0.166M[/tex]
[tex][O_2]_{eq}=0.145M[/tex]
Plugging values in equation 1, we get:
[tex][NO]=\sqrt{(1.2\times 10^{-4})\times 0.166\times 0.145}[/tex]
[tex][NO]=\sqrt{2.88\times 10^{-6}}[/tex]
[tex][NO]=0.0017 M[/tex]
Hence, the concentration of NO is 0.0017 M.
BRAINIEST AND POINTS
Which option below accurately describes the relationship between frequency and wavelength?
A. The higher the frequency the shorter the wavelength.
B. The lower the frequency the shorter the wavelength.
Answer:
Hi, there your answer is A. As the frequency of a wave increases, the shorter its wavelength is.
Explanation:
When frequency increases, wavelength decreases.
Hope this Helps :)
Look at the table of dissociation constants for some acids.
Acid Ka Acetic acid 18 x 10-6 1.2 x 10-2 Chlorous acid Nitrous acid 4.0 x 10 -4 Propionic acid 1.3 x 10-5
Which of these is the strongest acid?
acetic acid
chlorous acid
nitrous acid
propionic acid
*Answer is B*
Answer:
chlorous acid
Explanation:
The acidic equilibrium of weak acids, HX, occurs as follows:
HX ⇄ H+ + X-
Where Ka is written as:
Ka = [H+] [X-] / [HX]
The strongest acid is the acid that produce more H+. The acid with the higher Ka is the acid that produce more [H+] and is, thus, the strongest acid.
The higher Ka is the Ka of chlorus acid = 1.2x10-2
Right answer is:
chlorous acidAnswer:
chlorous acid :)
Explanation:
Im stuck on these two questions anyone have the right answer?
When you test starch with Barfoed’s reagent, what would be the answer, positive or negative?
Answer:
It would test positive.
g What is the relationship between the moles of the limiting reagent and the change in temperature (i.e. directly proportional or indirectly proportional)
Answer:
number of moles is inversely proportional to the Temperature
Explanation:
As we know
PV = nRT
where P is the pressure
V is the volume
n is the number of moles
R is the gas constant
and T is the temperature
If we see the equation, we can find that n is inversely proportional to the Temperature
A student went to the cafeteria and bought iced tea. He then proceeded to add more sugar to his iced tea. In this solution, the iced tea was the __________ and the sugar was the ____________.
A student enters the canteen and buys iced tea. He then goes on to add more sugar to his iced tea. In this solution, iced tea is the solvent and sugar is the solute.
A 750-mL sample of hydrogen exerts a pressure of 822 torr at 325 K. What pressure does it exert if the temperature is raised to 475 K at constant volume
Answer:
1.20 × 10³ torr
Explanation:
Step 1: Given data
Initial pressure (P₁): 822 torrInitial temperature (T₁): 325 KFinal pressure (P₂): ?Final temperature (T₂): 475 KConstant volume: 750 mLStep 2: Calculate the final pressure of the gas
Considering the constant volume, if we assume the gas behaves ideally, we can calculate its final pressure using Gay-Lussac's law.
P₁/T₁ = P₂/T₂
P₂ = P₁ × T₂/T₁
P₂ = 822 torr × 475 K/325 K = 1.20 × 10³ torr
A plastic rod that have just been rubbed with a fur and kept near a negatively charged ballon that is freely suspended. The charged balloon moves away from the plastic. What does this explain you ?
Explanation:
that both the plastic & balloon have the same charge