Answer:
V=10 l H2O
VM=22.4 l/mole
n=V/Vm=0.446 moles H2O
the ratio 1:2
x:0.446
x=0.223 moles O2
Which animal is in higher trophic level dolphins or plankton
A radioactive isotope has a half-life of 9 hours. find the amount of the isotope left from a 360-milligram sample after 36 hours. if necessary, round your answer to the nearest thousandth.
Answer:
22.5 mg
Explanation:
36 hrs / 9 hr/half life = 4 half lives
(1/2)^4 * 360 = 22.5 mg
9. The use of lubricants makes the surface
(a) Rough
(b)Smooth
(c)Very Rough
(d)None of the above
Answer:
B
Explanation:
preform the following mathematical operation, and report the answer to the correct number of significant figures
1.235 x 2.65 = ?
As lowest significant is 2.65
It should be rounded till second decimal
3.2733.2772.
How many atoms are present in one mole of
water?
A)54
B)3
C)3(6.02 × 1023)
D)6.02 x 1023
Answer:
3 atoms
Explanation:
A water molecule consists of three atoms an oxygen atom and two hydrogen atoms which are bond together like little magnets
Which element could be included in a hydrocarbon?
Ca
Zn
Cl
Sn
Answer:
Cl
Explanation:
Hydrocarbons are Carbon chains that contain at least one halogen (F, Cl, Br, I and At)
Cl is a halogen
(I got this right on the test too)
Convert 1060 mm Hg to atm. (answer should include 3 sig. fig and NO LABEL)
Answer:
1.39
Explanation:
1060 mm / 760 mm/atm = 1.39 atm
What does a positive value of A Gº mean for a reaction?
O A. The reaction is spontaneous if AS<0.
O
B. The reaction is spontaneous.
C. The reaction is spontaneous if A S> 0.
D. The reaction is nonspontaneous.
Answer:
D
Explanation:
If delta G at standard conditions is positive, then the reaction will always be nonspontaneous in the forward direction.
what are chemical changes in chemistry
a usually irreversible chemical reaction involving the rearrangement of the atoms of one or more substances and a change in their chemical properties or composition, resulting in the formation of at least one new substance: The formation of rust on iron is a chemical change. Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
Explain why hydrogen chloride is a gas at room temperature
The hydrogen chloride is a gas at room temperature due to the presence of weak intermolecular forces.
What is hydrogen chloride?Hydrogen chloride (HCl) is a chemical compound in which polar covalent bond is present between hydrogen atom and chlorine atom.
This bond is not so strong enough to maintain the stability in the liquid phase, else they are weak intermolecular forces and easily gets break through small amount of energy and having low boiling point. That's why HCl is present in gaseous state at room temperature.
Hence due to weak intermolecular force, HCl is present in gaseous state.
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Use the drop-down menus to answer the questions. Which type of radioactive decay produces particles with a positive charge and very small mass? Which type of radioactive decay produces radiation with zero mass? Which type of radioactive decay produces radiation that requires lead shielding? Which type of radioactive decay produces radiation that can be stopped by a sheet of paper? Which type of radioactive decay produces particles with the most mass?.
Answer:
beta, gamma. gamma. alpha, alpha
Explanation:
Answer:
1. Beta
2. Gamma
3. Gamma
4. Alpha
5. Alpha
Explanation:
give maximum 3 examples each for exothermic and endothermic reaction.
like :- N2+O2---->2NO
Explanation:
Exothermic reactions are those reactions in which heat is released.
Reactants→products+heat
For example, formation of ammonia from nitrogen and hydrogen is an exothermic reaction.
N2(g)+3H2(g)→2NH3(g)+92.2kJ
Endothermic reactions are those reactions in which heat is absorbed.
Reactants+heat→products
For example, dissociation of ammonia into nitrogen and hydrogen is an endothermic reaction.
2NH3 (g)+92.2kJ→
N2(g)+3H2(g)
ANSWER ASAP!!!! PLS HELP
Answer: increase
Explanation: as pressure is increased, equlilibrium shifts towards the side with less moles of gas.
PLEASE ANSWER THIS ASAP!!!!!!:Was the erosion in this image a result of physical or chemical weathering?
Answer:
physical
Explanation:
the snow caused the erosion.
Answer:
physical
Explanation:
Which of the following is not a molecular formula?
N₂020
N₂08
N₂04
NO₂
Answer:
N2020
Explanation:
I’m not fully sure but I’m pretty sure it’s wrong
can someone please help meeeee (im doing map)
Hydrazine is a colourless fuming corrosive strongly reducing liquid base [tex]N_2H_4[/tex] used especially in fuels for rocket and jet engines. And [tex]2H_2[/tex](g) is used to prepare hydrazine. Hence, option B is correct.
[tex]N_2(g)+2H_2(g)[/tex] → [tex]N_2H_4(g)[/tex]
What is hydrazine?Hydrazine is a chemical compound with the formula [tex]N_2H_4[/tex]. It has an ammonia-like odour, but the properties are more similar to water.
Chemical equation of the formation of hydrazine:
[tex]N_2(g)+2H_2(g)[/tex] → [tex]N_2H_4(g)[/tex]
Hence, option B is correct.
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Calculate the mass of Sb produced when 0.122 moles of is produced. Show work.
Answer:
14.9 g Sb
Explanation:
The mass of Sb produced can be calculated using the conversion:
Molar Mass (g/mol) = mass (g) / moles
Antimony (Sb) has the molar mass 121.76 g/mol. This value is found on the periodic table. You have been given the moles produced. Therefore, you can find the mass of Sb by plugging these values into the formula and simplifying.
Molar Mass = mass / moles
121.76 g/mol = mass / 0.122 moles
14.9 = mass
There is no such thing as a(n) ___ gas.
Answer:
Ideal?
Explanation:
This question is lacking context, but it's most likely looking for ideal. There is an idea of "ideal" gasses, which are gasses the behave according the ideal gas law PV=nRT. The concept is the gasses can get very close to behaving ideally, but there is never a gas the will perfectly obey the ideal gas law. There are many factors that affect this, but I won't get into thoes since that's not what the question asked.
Water is a pure substance. Which of the following iS true about water?
O Its
compounds can only be chemically separated into the elements that make it up.
Its
compounds can only be physically separated into the elements that make it up.
® It is made up of a variety of compounds, each with a different set of properties.
® It is made up of one element and one compound, each with the
same properties.
Answer:
Explanation:
a.) Its compounds can only be chemically separated into the elements that make it up.
Water's compounds can only be chemically separated into the elements that make it up. The elements that make up water are two hyrdogen atoms and one oxygen. They only way to break down water is to return to the original three atoms.
I HOPE THIS HELPS & good luck <3 !!!!
0. 300 moles of sodium nitrite are needed for a reaction
Molar concentration is the ratio of the moles and the volume. The volume of the solution that is needed is
What is Molarity?Molarity or the molar concentration is the proportion of the moles of the solute to the volume of the solution in liters.
Given,
The molar concentration of the solution = 0.450 mol/L
Moles of sodium nitrite = 0.300 moles
Volume is calculated as:
[tex]\begin{aligned} \rm volume &= \rm \dfrac{moles}{molarity}\\\\&= \dfrac{0.300}{0.450}\\\\&= 0.666 \;\rm L\end{aligned}[/tex]
Therefore, 666 mL of volume is needed.
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An owl eats its pray whole or in large pieces summarize what is found in an owl pellet and why it is regurgitated
Answer:
it is regurgitated and an owl pellet
An element in Group 2 of the periodic table likely has which characteristics?
Answer:
Shiny solid. Conducts heat and electricity. Easily bends
Explanation:
CH3COOH CH3COO– + H+
You start with 0.05 moles of acetic acid in 500 mL of water. At equilibrium, the pH of the solution is 2.873. What is the equilibrium constant of this reaction? Hint: You will need to calculate an antilog using a scientific calculator.
(a)
pH = 4.77
; (b)
[
H
3
O
+
]
=
1.00
×
10
-4
l
mol/dm
3
; (c)
[
A
-
]
=
0.16 mol⋅dm
-3
Explanation:
(a) pH of aspirin solution
Let's write the chemical equation as
m
m
m
m
m
m
m
m
l
HA
m
+
m
H
2
O
⇌
H
3
O
+
m
+
m
l
A
-
I/mol⋅dm
-3
:
m
m
0.05
m
m
m
m
m
m
m
m
l
0
m
m
m
m
m
l
l
0
C/mol⋅dm
-3
:
m
m
l
-
x
m
m
m
m
m
m
m
m
+
x
m
l
m
m
m
l
+
x
E/mol⋅dm
-3
:
m
0.05 -
l
x
m
m
m
m
m
m
m
l
x
m
m
x
m
m
m
x
K
a
=
[
H
3
O
+
]
[
A
-
]
[
HA
]
=
x
2
0.05 -
l
x
=
3.27
×
10
-4
Check for negligibility
0.05
3.27
×
10
-4
=
153
<
400
∴
x
is not less than 5 % of the initial concentration of
[
HA
]
.
We cannot ignore it in comparison with 0.05, so we must solve a quadratic.
Then
x
2
0.05
−
x
=
3.27
×
10
-4
x
2
=
3.27
×
10
-4
(
0.05
−
x
)
=
1.635
×
10
-5
−
3.27
×
10
-4
x
x
2
+
3.27
×
10
-4
x
−
1.635
×
10
-5
=
0
x
=
1.68
×
10
-5
[
H
3
O
+
]
=
x
l
mol/L
=
1.68
×
10
-5
l
mol/L
pH
=
-log
[
H
3
O
+
]
=
-log
(
1.68
×
10
-5
)
=
4.77
(b)
[
H
3
O
+
]
at pH 4
[
H
3
O
+
]
=
10
-pH
l
mol/L
=
1.00
×
10
-4
l
mol/L
(c) Concentration of
A
-
in the buffer
We can now use the Henderson-Hasselbalch equation to calculate the
[
A
-
]
.
pH
=
p
K
a
+
log
(
[
A
-
]
[
HA
]
)
4.00
=
−
log
(
3.27
×
10
-4
)
+
log
(
[
A
-
]
0.05
)
=
3.49
+
log
(
[
A
-
]
0.05
)
log
(
[
A
-
]
0.05
)
=
4.00 - 3.49
=
0.51
[
A
-
]
0.05
=
10
0.51
=
3.24
[
A
-
]
=
0.05
×
3.24
=
0.16
The concentration of
A
-
in the buffer is 0.16 mol/L.
hope this helps :)
The equilibrium constant of this reaction is 1.80×10-5
Given data,
pH of solution = 2.873
Number of moles of acetic acid (m) = 0.05 moles
Volume of water (V) = 500 mL = 0.5L
So, concentration (C) = m/V in lit = 0.05/0.5 = 0.1 M
Equilibrium constant ( K ) = [tex][CH_{3} COO-][/tex]×[tex][H+_{} ][/tex]/[tex][CH_{3} COOH][/tex]
Since, acetic acid is weak acid,
So, Equilibrium constant ( K ) = [tex][H+]^{2}[/tex]/[tex][CH_{3} COOH][/tex] ....(i)
As the pH = 2.873, the [tex][H+_{} ][/tex] is antilog of -2.873 or 1.34×10-3 M.
Putting the value of concentration of [tex]H+_{}[/tex] and [tex]acetic_{} acid[/tex] in equation (i).
Equilibrium constant ( K ) = 1.80×10-5
What is weak acid ?The acid which is partially dissociates into ions on dissolving in aqueous solution is called weak acid.
Example: [tex]acetic_{} acid[/tex].
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a hydrochloric acid solution HCI has a concentration of 12.1 M. A 41.2 mL sample is used to make a more dilute solution. If the new solution has a concentration of 0.5 M determine the volume of the solution
If the new solution has a concentration of 0.5 M, then the volume of the solution is 997mL.
How do we calculate the required volume?Required volume of the new solution will be calculated by using the below equation as:
M₁V₁ = M₂V₂, where
M₁ & V₁ are the molarity and volume of initial HCl solution.
M₂ & V₂ are the molarity and volume of final HCl solution.
On putting values from the question, to the above question we get:
V₂ = (12.1)(41.2) / (0.5) = 997 mL
Hence resultant volume of the final solution is 997 mL.
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In the important industrial process for producing ammonia (the Haber Process), the overall reaction is:
N2(g) + 3H2(g) → 2NH3(g) + 100.4 kJ
A yield of NH3 of approximately 98% can be obtained at 200°C and 1,000 atmospheres of pressure.
This reaction is:
endothermic or exothermic? (please answer) thanks for any help:) it mean a lot
Answer:
The reaction is exothermic.
you are working as an analytical ghemist at a university. an archeologist is studying a village
dating to 800 to 1000 years ago brings you a sample of charcoal from a dig site 300 meters from
the main village site. the archeologist asks you to analyze the sample to see if it could be from a
new part of the village or was it naturally occurring. what is the scientific question the
archeologist is asking of you?
The scientific question that is being asked by the archeologist is the age of the sample.
What is a scientific question?A scientific question is a question that can be answered empirically. That is, the question can be answered through an experiment.
Given the explanation in the question, the scientific question that is being asked by the archeologist is the age of the sample.
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What is the hydronium ion concetration of a ph=9. 2 solution
The hydronium ion concentration of a pH = 9.2 of solution is 6.3 × 10⁻¹⁰M.
How do we calculate pH?pH of the solution is define as the negative logarithm of the concentration of the hydronium ion as:
pH = -log[H⁺]
Or [H⁺] = [tex]10^{-pH}[/tex]
Given that pH value = 9.2
On putting values, we get
[H⁺] = [tex]10^{-9.2}[/tex] = 6.3 × 10⁻¹⁰M
Hence required concentration of hydronium ion is 6.3 × 10⁻¹⁰M.
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Which element is reduced in this reaction? 2kmno4 3na2so3 h2o→2mno2 3na2so4 2koh
In a redox chemical reaction, one species gets reduced and another gets oxidized. Manganese element is reduced in this reaction.
What is oxidized and reduced?In a redox reaction, the increase or decrease in the oxidation number and electrons results in the reduction and oxidation of the chemical species. The oxidation and reduction occur simultaneously in a reaction.
The oxidation number of Mn in permanganate ion was +8 on the left side and decreased to +4 on the right side of the equation. Potassium permanganate is an oxidizing agent that has reduced the manganese ion of the permanganate ion.
Therefore, manganese is reduced.
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?? Answeeeeeeer
Answerrrrrrrrr
Answer:
.00000005 C or 50 x 10^-9 C
Explanation:
Like charges REPEL
k = 8.99 x 10^9 kg m^3 / s^2 C^2 ( they should have given units of this)
F = k q1q2/r^2 q1 = q2 so
F = k q^2 / r^2
9 x 10^-3 = 8.99 x 10^9 * q^2 /.05^2 (.05 m = 5cm)
q = .00000005 C
Find the percent yield of both experiments 1.magnesium
2.copper carbonate
The the percent yield of the given reactions is the ratio of the actual yield and the theoretical yield expressed as a percentage.
What is percent yield of a reaction?The percent yield of a reaction is the ratio the actual yield and the theoretical yield of a reaction expressed as a percentage.
Percent yield = actual yield/theoretical yield × 100%The actual yield is obtained from the experiment while the theoretical yield is obtained from the equation of the reaction.
The percent yield of a reaction gives an indication of how efficient the reaction conditions were.
The equation of the reaction in the given question is not stated.
Therefore, the percent yield of the given reactions is the ratio of the actual yield and the theoretical yield expressed as a percentage.
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