A 1.775g sample mixture of KHCO₃ is decomposed by heating. if the mass loss is 0.275g, the mass percentage of KHCO₃ is 70.4%.
What is a decomposition reaction?A decomposition reaction can be defined as a chemical reaction in which one reactant breaks down into two or more products.
Step 1: Write the balanced equation for the decomposition of KHCO₃.2 KHCO₃(s) → K₂CO₃(s) + CO₂(g) + H₂O(l)
The mass loss of 0.275 g is due to the gaseous CO₂ that escapes the sample.
Step 2: Calculate the mass of KHCO₃ that formed 0.275 g of CO₂.In the balanced equation, the mass ratio of KHCO₃ to CO₂ is 200.24:44.01.
0.275 g CO₂ × 200.24 g KHCO₃/44.01 g CO₂ = 1.25 g KHCO₃
Step 3: Calculate the mass percentage of KHCO₃ in the sample.There are 1.25 g of KHCO₃ in the 1.775 g sample.
%KHCO₃ = 1.25 g/1.775 g × 100% = 70.4%
A 1.775g sample mixture of KHCO₃ is decomposed by heating. if the mass loss is 0.275g, the mass percentage of KHCO₃ is 70.4%.
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4. The students predict that the reaction will release a lot of energy. What question could help
provide support for the prediction?
Take a reaction among lime water
[tex]\\ \rm\rightarrowtail CaO+H_2O=Ca(OH)_2[/tex]
If it releases heat
The question must include
+Heat sign or ∆ symbol∆H must be +veAnswer:
hope it's helpful to you
A student has a sample of isopropanol (C3H7OH) that has a mass of 78. 6 g. The molar mass of isopropanol is 60. 1 g/mol. How many moles of isopropanol are contained in this sample? 0. 765 moles 1. 31 moles 78. 6 moles 4,720 moles.
Mole is the ratio of the mass to the molar mass of the substance and its unit is mol. The moles of isopropanol in the sample are 1. 31 moles.
What are moles?Moles are the unit of measurement of the smallest entity of atoms, molecules, and compounds.
Given,
Mass of isopropanol (m) = 78. 6 g
Molar mass of isopropanol = 60. 1 g/mol
Moles of isopropanol is calculated as:
[tex]\begin{aligned} \rm moles (n) &= \rm \dfrac{mass}{molar \; mass}\\\\&= \dfrac{78.6}{60.1}\\\\&= 1.31\;\rm moles\end{aligned}[/tex]
Therefore, moles of isopropanol are option b. 1.31 moles.
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Which is a disadvantage of using chemical indicators? they are expensive to use. they measure ph directly. they must be selected for a narrow ph range. they do not use electricity to operate.
Chemical indicators are the chemical reagents that show the change in reaction by changing color. Chemical indicators must be chosen with a narrow pH range.
What are indicators?Indicators are the solutions or the substances used for the qualitative and the quantitative measurement by a change in color because of the absence or the presence of the sample concentration.
The chemical indicators cannot detect the exact pH and should be used with a narrow range of pH.
Therefore, option C. the narrow range of pH is the disadvantage of chemical indicators.
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Answer:
C (They must be selected for a narrow ph range.
Explanation:
Edg 2022
For many Arrhenius acid base reactions (e.g., NaOH HCl, or KOH HNO3) the enthalpy change is the same regardless of which acid and which base are used. Why do you think this is so
Answer:
that's because
Explanation:
as far as my knowledge is concerned
HCl(g) + H2O ⇄ H3O+ (aq) + Cl– (aq)
or, more simply (and truer to the original theory):
HCl(g) ⇄ H+ (aq) + Cl– (aq) or HCl(aq)
Which of these form electrolytic solutions with water?
Multiple answers.
A) Sodium Chloride (NaCl)
B) Glucose (C6H12O6)
C) Hydrochloric acid (HCl)
D) Carbon Dioxide (CO2)
Answer:
I believe is the correct answer
Explanation:
a
Given what you observe at the molecular/atomic level, why would surface area have this effect?
Answer:
Increasing the surface area of a reactant increases the frequency of collisions and increases the reaction rate. Several smaller particles have more surface area than one large particle. The more surface area that is available for particles to collide, the faster the reaction will occur.
Explanation:
:)
Would the ph at the equivalence point be acidic, basic, or neutral for each given titration?.
The pH at equivalence point depends on the nature of the acid-base titration, and can either be acidic, basic, or neutral.
What is equivalence point?The equivalence point in a titration is the point at which equal amount of acid and base have reacted with each other.
The pH at equivalence point depends on the nature of the acids and bases being titrated.
pH at equivalence point will be:
neutral in a strong acid and strong base titrationacidic in a strong acid and weak base titration basic in a weak acid and strong base titrationTherefore, the pH at equivalence point depends on the nature of the acid-base titration.
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4. when cu(oh), is heated, it decomposes to black cuo and h,o. consider, how
many grams of cuo will be formed from the decomposition of 6.59 g of cu(oh)?
if only 5.17 g of cuo are produced instead, what is the percent yield?
The percent yield of CuO is 96%. The percentage yield shows the extent to which reactants are converted to products.
What is percent yield?The percent yield is the actual yield divided by the theroretical yield multiplied by 100.
Now we have the equation;
2Cu(OH)2 → 2CuO + 2H2O
Number of moles of Cu(OH)2 = 6.59 g/98 g/mol = 0.067 moles
Since 2 mole of Cu(OH)2 yeilds 2 moles of CuO
0.067 moles alos yields 0.067 moles of CuO
Mass of CuO = 80 g/mol * 0.067 moles of CuO = 5.36 g
Hence, percent yield = 5.17 g/5.36 g * 100 = 96%
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SCIENCE help pls need kna
I answered your question in the photo sent
Good luch
476 nm = [? ]10
cm
give your answer in scientific notation.
1nm=10^-6 cm.
476 nm = 4.76E-5 cm
What is the coefficient of the permanganate ion when the following equation is balanced? mno4- br- → mn2 br2 (acidic solution)
In acidic solition, the coefficient of permanganate ion in the balanced redox equation is 2.
How can a redox equation be balanced?A redox equation showing a reduction and an oxidation reaction occurring simultaneously.
To balance redox equations, the atoms reacting as well as the electrons transferred are balanced.
In the reaction of permanganate ion and bromide ion in acidic solution, the balanced redox equation is given as follows:
2 MnO4- + 10Br- + 16 H+ → 2 Mn2+ 5 Br2 + 8 H2OTherefore, the coefficient of permanganate ion in the balanced redox equation is 2.
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The coefficient of the permanganate ion of the MNO₄ - Br- → MN₂ + Br₂ is 2.
What is a redox reaction?A redox equation depicting a simultaneous reduction and oxidation reaction.
The atoms reacting as well as the electrons transferred must be balanced to balance redox equations.
The balanced redox equation for the reaction of permanganate ion and bromide ion in acidic solution is:
[tex]\rm 2 MnO_4- + 10Br^- + 16 H^+ \rightarrow2 Mn_2+ 5 Br_2 + 8 H_2O[/tex]
Thus, the coefficient of the permanganate ion of the MNO₄ - Br- → MN₂ + Br₂ is 2.
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60 points! please help me! i will appreciate it
Answer:
[tex]\huge\boxed{\sf v = 0.017 \ L}[/tex]
Explanation:
Given Data:
Mass = m = 0.08 g
Molar mass of C₂H₂F₄ = (12×2) + (1×2) + (19×4)
= 24 + 2 + 76 = 102 g/mol
Pressure = P = 1.14 atm
Temperature = T = 19.1 °C + 273 = 292.1 K
Gas Constant = R = 0.08206 L atm K⁻¹ mol⁻¹
Required:
Volume = v = ?
Formula:
Pv = nRT
Solution:
Firstly, finding moles (n)
[tex]\displaystyle n = \frac{mass}{molar \ mass} \\\\n = \frac{0.08 }{102} \\\\n =0.0008 \ mol[/tex]
Now, Finding volume (v)
Rearranging formula
[tex]\displaystyle v = \frac{nRT}{P} \\\\v = \frac{(0.0008)(0.08206)(292.1)}{1.14} \\\\v = \frac{0.019}{1.14} \\\\v = 0.017 \ L\\\\\rule[225]{225}{2}[/tex]
what describes the equivalence point on a graph of pH versus the amount of titrant added to a solution
Answer:
Titrant and analyte is a pair of acid and base. ... Equivalence point: point in titration at which the amount of titrant added is just enough to completely neutralize the analyte solution. At the equivalence point in an acid-base titration, moles of base = moles of acid and the solution only contains salt and water.
Explanation:
Draw the alkyl bromide(s) you would use in a malonic ester synthesis of ethyl 2-methyl-4-pentenoate
The structure of the alkyl bromides used in a malonic ester synthesis of ethyl 2-methyl-4-pentenoate are as drawn in the attached image.
Ethyl 2-methyl-4-pentenoate by Malonic ester synthesis.The malonic ester synthesis is a chemical reaction characterized by the alkylation of diethyl malonate or a similar ester of malonic acid at the carbon alpha (directly adjacent) to both carbonyl groups, and subsequently converted to a substituted acetic acid.
Hence, it follows from the structure of Ethyl 2-methyl-4-pentenoate that the alkyl bromides used are Ethyl bromide and methyl bromide.
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The structure of alkyl bromide that would be used in a malonic ester synthesis of ethyl 2-methyl-4-pentenoate are ethyl bromide and methyl bromide.
What is alkyl bromide?
When halogens such as Br, Cl, I, attched to the sp3 carbon atom of alkyl group, they called alkyl halides.
Here, bromide is attached to an alkyl group.
Ethyl bromide and methyl bromide are the alkyl halides used in synthesis of ethyl 2-methyl-4-pentenoate
Thus, ethyl bromide and methyl bromide are the alkyl bromides.
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___________ in the stomach are responsible for the mechanical digestion that takes place there.
By titration, 13.5 mL of aqueous H2SO4 neutralized 21.8 mL of 0.0419 M LiOH solution. What was the molarity of the aqueous acid solution?
13.5 mL of 0.0339 M H₂SO₄ is titrated with 21.8 mL of 0.0419 M LiOH.
What is titration?Titration is a process of chemical analysis in which the quantity of some constituent of a sample is determined by adding to the measured sample an exactly known quantity of another substance with which the desired constituent reacts in a definite, known proportion.
Step 1: Write the balanced equation.H₂SO₄ + 2 LiOH ⇒ Li₂SO₄ + 2 H₂O
Step 2: Calculate the reacting moles of LiOH.0.0218 L × 0.0419 mol/L = 0.000913 mol
Step 3: Calculate the reacting moles of H₂SO₄.The molar ratio of H₂SO₄ to LiOH is 2:1.
0.000913 mol LiOH × (1 mol H₂SO₄/2 mol LiOH) = 0.000457 mol H₂SO₄
Step 4: Calculate the molarity of H₂SO₄.[H₂SO₄] = 0.000457 mol/0.0135 L= 0.0339 M
13.5 mL of 0.0339 M H₂SO₄ is titrated with 21.8 mL of 0.0419 M LiOH.
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What is the molarity of 20g of KNO, in 250 mL of water?
Answer:
should be 2M
Explanation:
:)
What is the molarity of a solution in which 25g NaCl in a 2.00 L solution?
Mass of sodium :- 23 grams
Mass of Chlorine :- 35.5 grams
Mass of NaCl :- 58.5 grams
mass given :- 25 grams
moles :- 0.432 ( given mass/ ionic mass)
[tex]molarity = \frac{moles}{vol} \\ molarity = \frac{0.432}{2} \\ molarity = 0.216 \: mole{l}^{ - 1} or \: molar[/tex]
What is equation for photosynthesis
Answer: The process of photosynthesis is commonly written as: 6CO2 + 6H2O → C6H12O6 + 6O2. This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products.
hope this helps!
Answer:
6CO2 + 6H2O → C6H12O6 + 6O2
Explanation:
Some bacteria live in the roots of plants like soybeans and peas.
Bacteria growing on plant roots.
What is the role of these bacteria in the nitrogen cycle?
to absorb nitrogen-containing compounds from the soil
to release free nitrogen into the atmosphere
to break down nitrogen-containing compounds in dead organisms
to convert free nitrogen into usable nitrogen
70 points!
Answer:
to release free nitrogen into the atmosphere. This is the answer.
Answer:
to convert free nitrogen into usable nitrogen
Explanation:
got it right on the test boi
What are the solutions to problems caused by nitrogen gas in solution at certain depths?
Please Help!!!! 50 points
The solutions to problems caused by nitrogen gas in solution at certain depths is by discouraging deep diving.
What is Diving?
This involves moving around under water with the aid of special breathing equipment.
Limiting the depth of a dive should he encouraged as the maximum depth limit for a diver to use compressed air is 30 to 50 meters.
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How are Dams good and Bad for the environment?
Help!!
Answer:
Dams can stop a place from flooding and give us electricity without creating pollution. It can also make a place dry and finish water for animals
Explanation:
The specific heat capacity of iron 0. 45 j/gk. Find the molar heat capacity for iron
Answer:
The final temperature of the sample is 21.004 °C
Explanation:
The molar heat capacity for iron is 25.130 J/g.c joules per gram per Kelvin.
What is molar heat capacity?The amount of heat needed to increase one temperature of one mole of a substance is called molar heat capacity.
By the formula [tex]\rm \Delta T^\circ c = \Delta Tk[/tex]
Given that c = 0.45 J/g.C
Molar mass of iron is 55.845
Then putting the values in the equation
[tex]c= 0.45 \times 55.845 \\\\c= 25.130 \;J/g.^\circ c[/tex]
Thus, the molar heat capacity for iron is 25.130 J/g.c
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What are the answers for The brainPOP digestive systems 1-10
Answer:
Q.
Why do we need to break apart the food we eat?
answer choices
so it can fit in our stomachs
so our bodies can use the nutrients from the food
so liquids can be separated from solids
so that our enzymes have something to do
2nd option
Where does digestion begin?
answer choices
mouth
stomach
large intestine
small intestine
first option
Q.
Chewing is an example of what kind of digestion?
answer choices
dental
fragmentary
chemical
mechanical
last option
If you wanted to find the glands that produce salivary amylase, where would you look?
answer choices
mouth
throat
intestines
stomach
first option
Place in order:
A. food enters large intestine
B. food enters small intestine
C. food enters esophagus
answer choices
A B C
C B A
C A B
B A C
2nd option
Hydrochloric acid can burn your skin yet it exists in your stomach. How can this be?
answer choices
small intestines absorb the acid
stomach lining protects you against burns
food in stomach absorbs the acid
the acid in your stomach is different from the acid in a chemistry lab
2nd option
What is chyme?
answer choices
a type of digestive enzyme
what food is called after it has been digested by the stomach
a chemically active part of the small intestine
a passage that leads from small to large intestine
2nd option
Q.
What might happen if you had your pancreas removed?
answer choices
your intestines might have trouble breaking down food
your stomach might have trouble producing hydrochloric acid
you would not be able to chew properly
you would have trouble producing saliva
first option
Q.
What is the main function of villi?
answer choices
to move food from the stomach to the small intestine
to absorb nutrients into the bloodstream
to absorb water from chyme
to move food from small intestine to large intestine
2nd option
Q.
What might happen if your large intestine did not absorb water from chyme?
answer choices
you couldn't digest food
you wouldn't be able to go to the bathroom
you'd become dehydrated
solid waste wouldn't be moved to the rectum
3rd option
Explanation:
I hope this helps
I got my answers in quiziz
Do the halogens tend to gain or lose electrons in chemical reactions? how many?
Explanation:
Halogens tend to gain one electron so that they can get a full outer level and be stable.
Assign an oxidation number to each element in the reaction. co(g) 2h2(g) → ch3oh(g) in co, the oxidation number of c is , and that of o is . in h2, the oxidation number of h is . in ch3oh, the oxidation number of c is , that of o is , and that of h is .
The oxidation state is the number of electrons gained and donated. The oxidation state of C is +2, O is -2, H is 0, and in methanol, C is +1, H is +1, and O is -2.
What is the oxidation number?The oxidation number denotes the number of electrons donated and gained after the bond formation. In general, the oxidation state of free elements is zero, and of hydrogen when the bond to non-metal is +1 and with metals is -1.
The chemical reaction is given as,
[tex]\rm CO + 2H_{2} \rightarrow CH_{3}OH[/tex]
Here,
The oxidation number of carbon in carbon monoxide will be +2, and oxygen will be -2.
The oxidation number of hydrogen in dihydrogen will be zero, and in methanol, the oxidation number of carbon will be +1, hydrogen will be +1 and oxygen will be -2.
Therefore, the oxidation number of oxygen is -2 most of the time.
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how many atoms of HCl are needed to produce 0.62 moles of hydrogen gas
Answer:
0.2 moles
Explanation:
The equation is given by;
2HCl => H² + Cl²
According to stoichiometry;
[tex] \frac{n \: hcl}{2} = \frac{n \: h {}^{2} }{1} [/tex]
[tex]nhcl = 2 \times nh {}^{2} [/tex]
To produce 0.62 moles of H² gas we need,
nHCL=2×0.62=1.24 moles
Using the relation;
number of moles:Number of atoms/Avogadro's constant
We can then say;
N(numb. of atoms)=n×Na
Number of atoms=1.24×6.02×10²³
Number of atoms=7.5852×10²³ atoms
Convert 18◦C to Kelvin.
291.15 Kelvin
I hope this helps
Answer:
18 degrees Celsius = 291.15 Kelvin
Explanation:
The formula for finding Kelvin through Celsius is by adding 273.15 to the Celsius. In this case, it is 18 + 273.15 = 291.15
:)
An ice cube is placed on the counter, as seen below. Draw an arrow to show the direction of heat transfer to or from the ice/water. Explain your answer.
Answer:
The arrow would be facing upwards from the counter to the icecube.
Explanation:
Heat flows from the counter to the ice causing the molecules in the counter to move more slowly.
An ice cube is placed on the counter, The arrow would be facing upwards from the counter to the ice cube. This is the property of water.
what are the properties of water molecule ?It is tasteless, odorless, or transparent, nucleus of the oxygen atom and the electrons strongly than the nuclei of the hydrogen atoms.
In water molecule oxygen is electro negative than hydrogen, results in the development of a partial negative charge on the oxygen and a partial positive charge on the hydrogen end.
Water have a strong cohesive property where the attraction of molecules with other molecules of the same kind is referred to as cohesion.
Surface tension of the water is defined as the tendency of the surface to resist rupture when they are subjected to stress due to cohesive forces.
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Write balanced equations and expressions for ksp for the dissolution of each of the following ionic compounds. Write a balanced equation for the dissolution of baso4
Based on the dissolution equation of BaSO4, the solubility product, Ksp, expression of BaSO4 is: [Ba^{2+}] × [SO4^{2-}]
What is solubility product Ksp of a solute?The solubility product, Ksp, of a substance is an equilibrium constant which expresses the product of the concentration of ions produced by a solute.
The solubility of a solute depends on temperature, thus solubility product also depends on temperature.
The balanced equation for the dissolution of barium sulfate is given below:
BaSO4 ⇌ Ba^{2+} + SO4^{2-}The solubility product for barium sulfate is given as;
Ksp = [Ba^{2+}] × [SO4^{2-}]
Therefore, the solubility product, Ksp, expression of BaSO4 is: [Ba^{2+}] × [SO4^{2-}]
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