Answer:
pH = 12.90
Explanation:
THe reaction of HNO₃ with KOH is:
HNO₂ + KOH → KNO₂ + H₂O
That means 1 mole of nitrous acid reacts per mole of potassium hydroxide.
To solve this question, we need to find the moles of each reactant:
Moles HNO₂:
0.0179L * (0.458mol / L) = 0.00820 moles
Moles KOH:
0.0334L * (0.368mol / L) = 0.01229 moles
That means KOH is in excess. The moles in excess are:
0.01229 moles - 0.00820 moles = 0.00409 moles KOH = Moles OH⁻
The [OH⁻] is -Total volume = 17.9mL+33.4mL = 51.3mL = 0.0513L-:
0.00409 moles / 0.0513L =
0.0797M =[OH⁻]
pOH = -log[OH⁻] = 1.098
pH = 14 - pOH
pH = 12.90The burning of fossil fuels, like coal, oil, and natural gas, DO NOT contribute to the presence of greenhouse gases in the atmosphere.
True
or
False
Answer:
false statements because they are all nonrenewable resources
HELPPP PLZZ
During lunch each day, Alex and Hailey have been noticing the trashcans around the lunchroom are filling rather quickly with cans and bottles. They decide a recycling program would be beneficial for their school and the environment, so they brainstorm ways to get the program started. Before discussing their idea with the principal, they need to decide which of their plans would best solve the problem. Which of their ideas would best solve the problem with the least amount of inconvenience (disturbance) for everyone involved? A) Ask volunteers to separate recyclable materials from the trash. B) Remove all vending machines that sell plastic bottles or aluminum cans. C) Get a petition started to build a recycling center close to the school. D) Place plastic and metal recycling bins next to each lunchroom trash can
Answer:
c
Explanation:
i think it is C but idek but to me it sounds like the best answers but tell me if im wrong pls give me feedback
The ideas that would best solve the problem with the least amount of inconvenience is to place plastic and metal recycling bins next to each lunchroom trash can.
What is recycling?The term recycling has to do with the reuse of a material after it has passed through certain processes. The idea of recycling is highly beneficial to the environment.
Thus, the ideas that would best solve the problem with the least amount of inconvenience (disturbance) for everyone involved is to place plastic and metal recycling bins next to each lunchroom trash can.
Learn more about recycling:https://brainly.com/question/11861824
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What is the concentration of a 22.35 L solution that contains 9.95 moles of sodium
acetate? Round your answer to the correct number of significant figures.
Answer:
0.445 M
Explanation:
Molarity = moles/Volume
M = 9.95/22.35 = 0.445 M
When developing a question for a scientific inquiry, the question will ideally
A.
not just simply ask why.
B.
identify variables.
C.
be measurable.
D.
all of these
Answer: https://brainly.com/question/2426371
Explanation: Someone already answered this, click the link. YW! :))
The face-centered cubic unit cell describing the structure of an ionic compound has an edge length of 207 pm. The lattice points of the unit cell are occupied by anions, and the cations are small enough so that the anions are in contact along the diagonal of the face of the unit cell. What is the ionic radius of the anion (in picometers)
Answer:
73.2 pm
Explanation:
"The anions make contact along the diagonal of the face of the unit cell, so the diagonal of the face is equal to 4 ionic anion radii. By letting r represent the ionic radius of the anion, d represent the diagonal of the face of the unit cell, and x represent the edge length, then d=4r and
d^2=x^2+x^2= 2x^2
By substituting 4r for d, the second equation becomes
(4r)^2=(2)x^2
Solving this equation for r shows that
r=(x–√2)/4
Since the edge length x is 207 pm, the ionic radius of the anion is
r= ((207 pm) X [tex]\sqrt{2}[/tex])/4=73.2 pm
Notice that the formulae used to describe atomic radii include constants with exact values. Therefore, these values do not constrain the number of significant figures."
The ionic radius of the anion in the FCC unit cell where anions are in contact along the diagonal of the face of the unit cell is 73.1pm.
What is ionic radius?Ionic radius is the distance between the center of the atom and the outermost part.
As in the question it is given that anions are in contact along the diagonal of the face of the unit cell, so the length of the diagonal is represented as: d = 4r, where
r = ionic radius
Length of edge i.e. a = 207 pm (given)
Two adjacent edges and diagonal of a FCC unit cell makes a right angle triangle, by using pythagoras theorem we can write as:
a² + a² = d²
2a² = (4r)²
2a²/16 = r²
2(207)²/16 = r²
85,698/16 = r²
0r r = 73.18 pm
Hence, 73.18 pm is the ionic radius of the anion.
To learn more about ionic radius, visit the below link:
https://brainly.com/question/8137711
At room temperature, oxygen is a gas and hydrogen is a gas. When they combine at room temperature, they form a _______________.
Answer: they can combine to form water or hydrogen peroxide.
Explanation:
sorry if it wrong i just looked it up lol. hope this helps tho
Analysis: Consider Joe's story. IF the test shows he does have Marfan syndrome, and if he inherited the Marfan gene from his mother, does this mean that his brother and sister also have it? You may want to draw up a Punnett Square or drawing to help you explain your answer. HINT: Is there any suggestion that he got a Marfan gene from his father?
We inherit genes from our biological parents in specific ways. One way is called autosomal dominant inheritance.
What is autosomal dominant inheritance?
Autosomal dominant inheritance means that the gene in question is located on one of the autosomes. These are numbered pairs of chromosomes, 1 through 22. (These chromosomes do not determine an offspring's gender.) Dominant means that only one gene from one parent is necessary to pass down a trait or a disorder. When a parent has a dominant trait or disorder, there is a 50 percent chance that any child he or she has will also inherit the trait or disorder:
Genetic illustration demonstrating autosomal dominant inheritance
Click Image to Enlarge
What is Marfan syndrome?
Marfan syndrome occurs in one of 5,000 live births. It is a connective tissue disorder associated with autosomal dominant inheritance. Connective tissue is abundant in the body and is important as a supporting structure. It is especially important for the musculoskeletal system. It also provides support for other body systems as well, including the eyes and the heart. The gene for Marfan syndrome is called fibrillin-1. This gene is localized to chromosome #15 on the long arm (q) at 15q21.1.
Common findings in individuals with Marfan syndrome include those related to connective tissue disorders. These include abnormal enlargement of the aortic root of the heart, dislocated lenses of the eyes, and a tall, lanky body with increased joint mobility, scoliosis, long flat feet, and long fingers. Findings may vary among individuals diagnosed with this condition, even within a family.
If an individual carries an abnormal gene for Marfan syndrome, that individual has a 50 percent risk of passing down the disorder to each future offspring. If a person does not carry the gene abnormality, then the risk for occurrence of the disorder in future offspring is the same as for the general population.
Explanation:
A factory in your town uses cadmium as part of its manufacturing process. Due to recent economic conditions, cadmium is no longer available, and you must find a replacement. Suggest two elements that might be good replacements. Which of these would be your choice? Explain why.
Answer:
Zn
Explanation:
PLZZZZ HELPP NOWW!!
According to the law of conservation of mass, what is the mass of water
formed in this reaction?
H2
+
02
32.00 g
2H20
?
2.02 g
A. 36.04 grams
B. 55.92 grams
C. 72.08 grams
D. 27.96 grams
Answer:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations.
According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.
Answer:
A. 36.04 grams
Explanation:
A.P.E.X
(a)A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
(i) What type of colour change do you observe?
(ii) Identify the type of reaction.
(iii) Write a word equation for the above change.
Answer: (i) blue colour fades away
(ii) Single replacement
(iii) copper sulphate + iron [tex]\rightarrow[/tex] iron sulphate + copper
Explanation:
Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
[tex]CuSO_4+Fe\rightarrow FeSO_4+Cu[/tex]
Here iron being more reactive than copper can easily displace copper from its salt solution and form iron sulphate and copper in elemental form.
The blue colour of the copper sulphate solution fades away.
The word equation is :
copper sulphate + iron [tex]\rightarrow[/tex] iron sulphate + copper
Who was the US president during the crisis?
a
Carter
bKennedy
CRegan
D
Washington
Answer:
D Washington hope it helps
Rocks are classified as sedimentary, metamorphic, or igneous on the basis of
the
a. age of the rocks.
b. way the rocks were formed.
c. types of fossils the rocks contain.
d. number of minerals found in the rocks.
How many moles are 9.9 * 1024 molecules of methane?
What is the enthalpy change(Q) when 60.0 g of NaOH is dissolved in one litre of water, given that the temperature of the solution increased by 15.8 °C?
Answer:
ΔH = -44.029 KJ/mol
Explanation:
We are told that 60.0 g of NaOH is dissolved in one litre of water.
From conversion, 1 litre = 1000 g
From tables, specific heat capacity of water; c = 4.18 J/g/°C
We are given ΔT = 15.8 °C
Formula for the heat absorbed by the solution is given as;
Q = mcΔT
Where;
Q = Heat gained by the water
m = Mass of the water
c = Specific heat of water
ΔT = change in temperature
Thus;
Q = 1000 × 4.18 × 15.8
Q = 66044 J
The solution absorbed 66044 J and therefore it means that the dissolution of the salt gave off 66044 J.
Thus;
Enthalpy is; ΔH = -66044 J
Now, Mass of NaOH is 60 g.
We know that molar Mass of NaOH is 39.997 g/mol. Thus;
Converting to moles, we have;
n = 60/39.997
n = 1.5 mol
Now, enthalpy when 1.5 moles of NaOH are dissolved in water will be;
ΔH = -66044 J/1.5 moles
ΔH = -44029.33 J/mol
ΔH = -44.029 KJ/mol
What unit of time is based on the revolution of Earth around the sun?
A. month
B. year
C. day
D. hour
The type of radioactive particle that can be stopped by a sheet of paper is the
A. alpha particle
B. beta particle
C. gamma ray
D. uranium
PLEASE HELP IMMEDIATE WORTH 10 POINTS
Fill in the blank with the word or phrase that best completes the statement or answers the question. The scientific name for a plant that reproduces with flowers is a(n)
Answer:
the scientific name is Angiosperms
Explanation:
please mark brainliest
"A bicycle's brakes apply 299 N of frictional force to the wheels as the bike moves 24 m
for 3.0 s. How much WORK do the brakes do?"
Answer:
0.62 N
Explanation:
first of all: 3.0 s = 0.05 m
Let ? be the work that brakes do at 3.0s
24 m ----> 299 N
0.05 m ---->?
? = (0.05 m x 299 N)/ 24
? = (14.95)/ 24
? = 0.622 N
How many grams of sulfur is there in 10.8 grams of sodium sulfate?
please help
Answer:
2.44 g S
Explanation:
One mole of Na2SO4 contains 1 mol of S.
Step 1: Find out the moles of Na2SO4:
10.8 g Na2SO4/MM Na2SO4
Step2: Find out the moles of S:
moles S = moles Na2SO4
Step 3: Find out the mass of S.
mass S = moles S x MM S
Dimensional analysis:
? g S = 10.8 g Na2SO4 x (1mol Na2SO4/MM Na2SO4) x (1mol S/1mol Na2SO4) x (MM S/ 1 mol S) = (10.8/142.04)x32.1 = 2.44 g S
The nucleus of an atom stays together only because the repulsive forces, called
forces, are overcome by
even stronger attractive forces.
fusion
nuclear
electrostatic
Answer:
Electrostatic
Explanation:
The forces that are overcome are the repulsive electrostatic forces between the protons (all charged positively).
Anybody Understand this question please help me !
Answer:
[tex]m_{Sn}=630.57gSn[/tex]
Explanation:
Hello!
In this case, according to the chemical reaction:
[tex]SnO_2+2H_2\rightarrow Sn+2H_2O[/tex]
We can evidence the 2:1 mole ratio between hydrogen and tin, thus, we perform the following stoichiometric setup to obtain the mass of produced tin:
[tex]m_{Sn}=21.46gH_2*\frac{1molH_2}{2.02gH_2}*\frac{1molSn}{2molH_2} *\frac{118.71gSn}{1molSn} \\\\m_{Sn}=630.57gSn[/tex]
Best regards!
What % of original U238 remains after three half lives?
1-50
2-25
3-12.5
4-6.25
Answer:
12.5
Explanation:
After three half-lives, one eighth (1/2 x 1/2 x 1/2) of the uranium-238 will remain. One-eighth equals 12.5%
PLZ HELP THIS IS DUE TODAY!!!!!!
Which statement BEST describes the motion of the molecules of a solid object
A They vibrate in place within a fixed volume.
B They move around freely within a fixed volume.
C They vibrate in place and take the shape of a container.
D They move around freely and take the shape of a container.
what is derived from sheep and goats that is used in break fluid
A bones and horns
B Fats and Fattys acids
C Manure
D Wool and Lanolin
the answer is A I took the test
Which obstacle was faced by African Americans serving in the armed forces during World War II?
They were forced to serve in segregated units.
They were not subject to military conscription.
ОООО
None of them ever saw combat during the war.
They were placed under French command.
Which statement describes a chemical property of sodium
A Sodium changes from a solid to liquid at a temperature of 97.8°C
B Sodium has the ability to react with chlorine and from a new substance.
C Sodium has destiny if 0.97 g/cm3.
D Sodium takes the form of a solid at room temperature
Answer:
Option b is show the chemical property of sodium....
What are the reasons to determine the melting point of a sample in a melting point apparatus? Select one or more:
A. U Assessment of the sample's purity
B. Conversion of the solid sample to liquid
C. Identification of an unknown sample
D. Removal of impurities from the sample
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the Choose... end of the tube down. Continue tapping until the sample Choose.. end of the tube down, tap the sample down slowly or Choose... to move the sample down Then, with the Choose... faster.
To prepare a sample in a capillary tube for a melting point determination, gently tap the tube into the sample with the a) open, b) closed end of the tube down. Continue tapping until the sample a) completely fills the tube b) is a couple millimeters high, c) has a single crystal in the tube. Then, with the a) closed, b) open end of the tube down, tap the sample down slowly or a) heat the tube up, b) drop the tube into a longer tube, c) shake the tube in the air to move the sample down faster.
Solution :
The reasons for the melting point determines :
the assignment of the sample's purityidentification of the unknown samplethe conversion of solid sample to the liquid completelyIn order to prepare the sample in the capillary tube for determining its melting point, we tap the tube gently into the sample with the open end of tube down. We then continue tapping the tube till the sample is couple of millimeters high.
Then the other close end of tube down, we tap the sample down again slowly or then dropping the tube into a longer tube so as to move down the sample faster.
Given 1.67 moles of K, how many moles of KBr are produced?
2 K+ 1 Br2---> 2 KBr
[tex]\displaystyle 1.67 \ mol \ KBr[/tex]
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
BracketsParenthesisExponentsMultiplicationDivisionAdditionSubtractionLeft to RightChemistry
Atomic Structure
MolesStoichiometry
Using Dimensional AnalysisAnalyzing Reactions RxNExplanation:Step 1: Define
[RxN - Balanced] 2K + Br₂ → 2KBr
[Given] 1.67 moles K
[Solve] moles KBr
Step 2: Identify Conversions
[RxN] 2 mol K → 2 mol KBr
Step 3: Stoichiometry
[DA] Set up conversion: [tex]\displaystyle 1.67 \ mol \ K(\frac{2 \ mol \ KBr}{2 \ mol \ K})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1.67 \ mol \ KBr[/tex]How many grams of a 26.9% sugar solution contain 49.0 g of sugar?
Answer:
182.156g
Explanation:
grams = 49/.269 = 182.156g needed
250 ml juice has 22 g sugar how sugar is in 2000ml of juice
Answer:
176 grams of sugar
explanation is down
Explanation:
250 / 22 = 2000 / x250 ml to 22 grams = 2000 ml to x grams
cross multiply
(250)(x) = (2000)(22)
250x = 44,000
x = 44,000/250
x = 176 grams of sugar