Answer:
0.0876L of 0.478M Na₃PO₄ are needed
Explanation:
The reaction of calcium chloride, CaCl₂, with sodium phosphate, Na₃PO₄ is:
3CaCl₂ + 2Na₃PO₄ → Ca₃(PO₄)₂ + 6NaCl
Where 3 moles of calcium chloride react with 2 moles of sodium phosphate to produce 1 mole of calcium phosphate.
To solve this question we need to find moles of CaCl₂ added. Using the reaction we can find the moles of Na₃PO₄ that are needed to react completely and the volume using its concentration:
Moles CaCl₂:
0.225L * (0.279mol / L) = 0.0628moles of CaCl₂
Moles Na₃PO₄:
0.0628moles of CaCl₂ * (2mol Na₃PO₄ / 3 mol CaCl₂) =
0.0419moles of Na₃PO₄
Volume 0.478M Na₃PO₄:
0.0419moles of Na₃PO₄ * (1L / 0.478mol) =
0.0876L of 0.478M Na₃PO₄ are neededWhich of the following statements does not describe the structure of an atom?
A) The electron cloud is a small and compacted space around the nucleus.
B) Inside the nucleus of an atom are protons and neutrons.
C) Protons are positively charged sub-atomic particles.
D) Electrons are negatively charged sub-atomic particles.
Classify each of the following compounds as a strong acid, weak acid, strong base, or weak base, and write the Ka expression for any weak acid or weak base:
1. [ Select ] ["strong base", "weak base", "strong acid", "weak acid"] LiOH
2. [ Select ] ["weak acid", "strong acid", "strong base", "weak base"] HF
3. [ Select ] ["strong acid", "weak acid", "strong base", "weak base"] HCl
4. [ Select ] ["weak base", "strong base", "weak acid", "strong acid"] NH3
Ka expression: [ Select ] ["[H+][F-] / [HF]", "[Li+][OH-]/ [LiOH]", "[H+][Cl-} / [HCl]", "[NH4+] / [NH3]", "[HF] / [H+][F-}", "[LiOH] / [Li+][OH-]", "[HCl] / [H+][Cl-}", "none"]
Calculate the concentration of OHLaTeX: -? in a solution that has a concentration of H+ = 7 x 10LaTeX: -?6 M at 25°C. Multiply the answer you get by 1010 and enter that into the field to 2 decimal places.
Answer:
See explanation below
Explanation:
There are several ways to know if an acid or base is strong. One method is calculating the pH. If the pH is really low, is a strong acid, and if it's really high is a strong base.
However we do not have a pH value here.
The other method is using bronsted - lowry theory. If an acid is strong, then his conjugate base is weak. Same thing with the bases.
Now, Looking at the 4 compounds, we can say that only two of them is weak and the other two are strong compounds. Let's see:
LiOH ---> Strong. If you try to dissociate :
LiOH ------> Li⁺ + OH⁻ The Li⁺ is a weak conjugate acid.
HF -----> Weak
HF --------> H⁺ + F⁻ The Fluorine is a relatively strong conjugate base.
HCl -----> Strong
This is actually one of the strongest acid.
NH₃ ------> Weak
Now writting the Ka and Kb expressions:
Ka = [H⁺] [F⁻] / [HF]
Kb = [NH₄⁺] [OH⁻] / [NH₃]
Finally, to calculate the [OH⁻] we need to use the following expression:
Kw = [H⁻] [OH⁻]
Solving for [OH⁻] we have:
[OH⁻] = Kw / [H⁺]
Remember that the value of Kw is 1x10⁻¹⁴. So replacing:
[OH⁻] = 1x10⁻¹⁴ / 7x10⁻⁶
[OH⁻] = 1.43x10⁻⁹ M
And now, multiplying by 10¹⁰ we have:
[OH⁻] = 1.429x10⁻⁹ * 1x10¹⁰
[OH⁻] = 14.29Hope this helps
Strong acids and bases are those which completely ionized in body fluid, and weak acids and bases are those who does not completely ionized in body fluid.
Ka expression is used to differentiate between strong and weak acids.
Which are strong acids and base and weak acids and bases?LiOH - strong baseHF - weak acidHCl - strong acidNH3 - weak baseWhat are the Ka expression of the following?Weak acid – HF[tex]\bold{\dfrac{[H+][F-]}{[HF]}}[/tex]
Weak base – NH3[tex]\bold{\dfrac{[NH_4^+] [OH^-]}{[NH_3]} }[/tex]
Calculate the concentration of OH?Given, [tex]\bold{ [H^+]=1\times10^-^6\; at \;25^oC}[/tex]
We know, [tex]\bold{ [H^+]\times[OH^-]=1\times10^-^6\; at \;25^oC}[/tex]
[tex]\bold{[OH^-]=\dfrac{1\times10^-^1^4}{6.2\times10^-^6} = 1.43\times10^-^9}[/tex]
Now, multiplying the value by [tex]10^1^0[/tex]
[tex]\bold{( 1.429\times10^-^9) \times 1\times10^1^0= 14.29}[/tex]
Thus, the value is 14.29.
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My labmate discovered a new compound and wanted to try to determine what it could be. We noticed that when mixed with an acid, it formed a white solid. What type of chemical reaction did the new chemical just undergo?
Answer:
it went under the process known as crystalization
Explanation:
am a chemist
A physical change does not involve a change in the substance’s chemical identity. Which of these statements describes a physical change?
Group of answer choices
A banana starts to smell as it ripens.
Onions taste sweeter after being cooked.
Aluminum cans get crushed before recycling.
Copper turns green when exposed to air.
Answer: the answer is C Aluminum cans get crushed before recycling.
Explanation:
Answer:
it will option C because it had no change in chemical reaction
What effect is climate change having on the amount of water in liquid, solid, and gas forms on Earth?
The change in entropy is related to the change in the number of moles of gas molecules. Determine the change in moles of gas for each of the reactions and decide if the entropy increases decreases or has little to no change.
The given question is incomplete. The complete question is:
The change in entropy is related to the change in the number of moles of gas molecules. Determine the change in moles of gas for each of the reactions and decide if the entropy increases decreases or has little to no change:
A. [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex]
B. [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)[/tex]
C. [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]
D. [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex]
Answer: A. [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex] : decreases
B. [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2(g)[/tex] : decreases
C. [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]: no change
D. [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex] : increases
Explanation:
Entropy is defined as the randomness of the system.
Entropy is said to increase when the randomness of the system increase, is said to decrease when the randomness of the system decrease and is said to have no change when the randomness remains same.
In reaction [tex]K(s)+O_2(g)\rightarrow KO_2(s)[/tex], as gaseous reactant is changed to solid product, entropy decreases.
In reaction [tex]CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)[/tex], as 4 moles of gaseous reactants is changed to 2 moles of gaseous product, entropy decreases.
In reaction [tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex], as 3 moles of gaseous reactants is changed to 3 moles of gaseous product, entropy has no change.
In reaction [tex]N_2O_2(g)\rightarrow 2NO(g)+O_2(g)[/tex] , as 1 mole of gaseous reactant is changed to 3 moles of gaseous product, entropy increases.
Allows ingestion and breaks down food so that nutrients can be absorbed???
Answer:
Salivation allows the ingestion of food while digestive juices aids breakdown of food and absorption of nutrients.
Explanation:
When food is taken into the mouth, the presence of food triggers a nervous reflex that causes the salivary gland to produce saliva in the mouth. Once the food particles have been ingested the digestive system breaks down the food into smaller components with the aid of the digestive juices.
helppp nowww plsss!!
Answer:
I believe its C but it could be B
Answer:A
Explanation: i would say the first one
After a recrystallization, a pure substance will ideally appear as a network of __________. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more _________
Answer:
Large crystals
Slowly
Explanation:
Recrystallization is a procedure used to purify an impure compound in a solvent. The concept used here is that the solubility of most of the solids increases with increase in temperature.
Recrystallization is also called as method of fractional crystallization.
After a recrystallization, a pure substance will ideally appear as a network of large crystals. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more slowly.
Which one has only 1 type of atom? compound element mixture solution
Answer:
look it updjk jkj vjx cv xckv
Explanation:
look it upvjcvjkcxjbvjkcvbjbcxkjvjdbfcvbdw uvd vjbvjfjv jdbv
Answer:
element :
a substance that is made up of only one type of atom
I hope it helps you ✌
What element has the same number of valence electrons as sulfur?
A cylinder containing CH4, C2H6, and N2 has to be prepared in which the ratio of the moles of CH4 to C2H6 is 1.3 to 1. Available are (1) a cylinder containing a mixture of 70% N2 and 30% CH4, (2) a cylinder containing a mixture of 90% N2 and 10% C2H6, and a cylinder of pure N2. Determine the proportions in which the respective gases from each cylinder should be used
Answer:
The proportions in which the respective gases from each cylinder should be used; C1 : C2 : C3 = 1 : 2.308 : C3
Explanation:
Given that;
CH4 to C2H6 = 1.3 to 1
Cylinder 1 = 70% N2 and 30% CH3
Cylinder 2 = 90% N2 and 10% C2H6
Cylinder 3 = ( pure N2 ) = 100% N2
CH4 to C2H6 = (1.3 to 1)
we have CH4 and C2H6 in cylinder 1 and 2 only
we only have balance material in c1 and c2
Now, Let x be from cylinder and ( 1-x ) be from cylinder 2
so, 30x / 10( 1-x ) = 1.3 / 1
30x = (10 - 10x)1.3
30x = 13 - 13x
30x + 13x = 13
x = 13/43
x = 0.3023
Also, ( 1-x ) = ( 1 - 0.3023) = 0.6977
so
C1/C2 = 0.3023/0.6977 = 1 / 2.308 while c3 can be anything;
Therefore, C1 : C2 : C3 = 1 : 2.308 : C3
1. How do organisms maintain homeostasis?
Answer:
Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them.
LaKeisha is measuring the density of a solid piece of metal using the graduated cylinder method. She initially measures a volume of water in the cylinder to be 3.28 mL. After placing the metal into the graduated cylinder, the new volume was 8.72 mL. The mass of the metal was 42.26 g on a top loading balance.
Required:
What is the density of the metal calculated to the correct number of significant figures?
Answer: 7.77 g/ml
Explanation:
Volume of cylinder with only water = 3.28 mL
Volume of cylinder with water and metal = 8.72 mL
Volume of metal = (Volume of cylinder with water and metal ) -(Volume of cylinder with only water)
=8.72-3.28
=5.44 ml
Mass of metal = 42.26 g
Formula of Density = [tex]\dfrac{\text{Mass}}{\text{Volume}}[/tex]
i.e. the density of the metal = [tex]\dfrac{42.26}{5.44}\approx7.77\text{ g/ml}[/tex]
Hence, the density of metal = 7.77 g/ml
In a laboratory setting, concentrations for solutions are measured in molarity, which is the number of moles per liter (mol/L). Concentrations are often converted to more common units on the labels of household products. For a particular brand of bleach, the concentration of sodium hypochlorite (NaClO) is reported on the bottle as 7.25% by mass. The following information can thus be used to calculate the molarity of NaClO in the bleach:
• 1L of bleach has a mass of 1,100 grams.
• 7.25% of the mass of bleach is NaClO.
• 1 mol of NaClO has a mass of 74.44 grams.
What is the molarity (mol/L) of NaClO in the bleach?
A.0.097
B.0.93
C.1.07
D.79.75
Answer:
its C
Explanation:
1/74.44 * 79.75 = 1.07
The molarity (mol/L) of NaClO in the bleach, given the data is 1.07 mol/L (Option C)
What is molarity?Molarity is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
How to determine the mass of NaClO in the bleachMass of bleach = 1100 gPercentage of NaClO = 7.25%Mass of NaClO = ?Mass of solute = percent × mass of solution
Mass of NaClO = 7.25% × 1100
Mass of NaClO = 0.0725 × 1100
Mass of NaClO = 79.75 g
How to determine the mole of NaClO Mass of NaClO = 79.75 gMolar mass of NaClO = 74.44 g/moleMole of NaClO =?Mole = mass / molar mass
Mole of NaClO = 79.75 / 74.44
Mole of NaClO = 1.07 mole
How to determine the molarity Mole of NaClO = 1.07 moleVolume = 1 L Molarity of NaClO =?Molarity = mole / Volume
Molarity of NaClO = 1.07 / 1
Molarity of NaClO = 1.07 mol/L
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If Juan had a glass of milk and dissolved 20g of chocolate milk powder into the milk, by how much will the mass of the milk go up by?
Answer:
20g or 0.2kg
Explanation:
this is because the mass of the powder is 20g and this will be added to the original mass of the milk causing it to increase by that amount
Answer: 20g
Explanation:
What is the main type of energy conversion that happens to a ball thrown in
the air as it goes up?
A. Kinetic energy to gravitational potential energy
B. Gravitational potential energy to kinetic energy
C. Chemical potential energy to kinetic energy
D. Kinetic energy to chemical potential energy
PLEASE HELPP!
Question #9
Long Text (essay)
Summarize the arguments both for and against allowing genetically altered meats into the United States.
B
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© 2013 Glynlyon, Inc.
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Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.ENVIRONMENTAL RISK. STRONGER CROPS = LESS PESTICIDES. REMEMBER WHEN CIGARETTES WERE 'HARMLESS'? TAMPERING FOR TASTE. ...BIG BUSINESS EATS SMALL FARMERS. ENHANCED HEALTH. NOTHING TASTES BETTER THAN NATURE.Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.
ENVIRONMENTAL RISK.
STRONGER CROPS = LESS PESTICIDES.
REMEMBER WHEN CIGARETTES WERE 'HARMLESS'?
TAMPERING FOR TASTE. ...
BIG BUSINESS EATS SMALL FARMERS.
ENHANCED HEALTH.
NOTHING TASTES BETTER THAN NATURE.
Explanation:
PLEASE HELP BRAINLIEST AND 15 points.
1. Which substance is nonvolatile ?
(1.5 Points)
Substance B, boiling point of 105 °C
Substance C, boiling point of 25 °C
Substance A, boiling point of 75 °C
Substance d, boiling point of 45 °C
Answer:
Substance B, boiling point of 105 °C
Explanation:
Non volatile substances have high boiling points
The pH of a sample of blood is 7.4, while gastric juice is pH 1.4. The blood sample has: Group of answer choices 0.189 times the [H ] as the gastric juice. 6 times lower [H ] than the gastric juice. one million times lower [H ] than the gastric juice 5.29 times lower [H ] than the gastric juice. 6000 times lower [H ] than the gastric juice.
Answer:
The blood sample has [H⁺] that is one million times lower than the [H⁺] of gastric juice.
Explanation:
To know the the correct answer to the question, we obtained obtained the hydrogen ion concentration [H⁺] of the blood and gastric juice. This can be obtained as follow:
For Blood sample:
pH = 7.4
Concentration of Hydrogen ion for blood [H⁺]₁ =?
pH = – Log [H⁺]₁
7.4 = – Log [H⁺]₁
Divide both side by –1
– 7.4 = Log [H⁺]₁
Take the antilog of – 7.4
[H⁺]₁ = Antilog (–7.4)
[H⁺]₁ = 3.98×10¯⁸ M
Thus, the concentration of Hydrogen ion for blood [H⁺]₁ is 3.98×10¯⁸ M
For Gastric juice:
pH = 1.4
Concentration of Hydrogen ion for gastric juice [H⁺]₂ =?
pH = – Log [H⁺]₂
1.4 = – Log [H⁺]₂
Divide both side by –1
– 1.4 = Log [H⁺]₂
Take the antilog of – 1.4
[H⁺]₂ = Antilog (–1.4)
[H⁺]₂ = 3.98×10¯² M
Thus, the concentration of Hydrogen ion for gastric juice [H⁺]₂ is 3.98×10¯² M
Finally, we shall compare the hydrogen ion concentration [H⁺] of the blood and gastric juice. This can be obtained as follow:
Concentration of Hydrogen ion for blood [H⁺]₁ = 3.98×10¯⁸ M
Concentration of Hydrogen ion for gastric juice [H⁺]₂ = 3.98×10¯² M
[H⁺]₁ / [H⁺]₂ = 3.98×10¯⁸ / 3.98×10¯²
[H⁺]₁ / [H⁺]₂ = 1×10¯⁶
Cross multiply
[H⁺]₁ = [H⁺]₂ × 1×10¯⁶
[H⁺]₁ = [H⁺]₂ / 1000000
From the calculations made above, the blood sample has [H⁺] that is one million times lower than the [H⁺] of gastric juice.
Were any of your substances difficult to identify as polar, nonpolar, or ionic? Explain.
Answer:
See explanation
Explanation:
A substance is classified as polar, nonpolar or ionic based on its behavior.
For the substances identified, there was no difficult in identifying each as polar, nonpolar, or ionic because since it was quite to easy identify where each belongs by looking out for whether it mixes or dissolves in our experiment.
Every substance in the experiment either mixed or dissolved during the experiment.
I need a help please!
Answer:
B. KBr + F2
Explanation:
In displacement reactions (reactions in which an element replaces another element in a compound) like these, reactive element displaces the less reactive element.
A. NaBr + I2
This reaction will not occur because Iodine is not able to displace bromine from the compound.
B. KBr + F2
This reaction will occur because flourine is more reactive and hence is able to displace bromine from the reaction.
C. LiF + Cl2
This reaction will not occur because chlorine is not able to displace flourine from the compound.
D. NaCl + I2
This reaction will not occur because Iodine is not able to displace Chlorine from the compound.
if a molecular formula is C8H12O2, what is the empirical formula
Answer:
C₄ H₆ O
Explanation:
The molecular formula of the compound is given as:
C₈ H₁₂ O₂
The molecular formula of a compound is expresses the true number of atoms within a compound.
The empirical formula gives the simplest ratio of the atoms within a compound.
Elements C H O
Number of atoms 8 12 2
Divide through by a
Common factor 8/2 12/2 2/2
4 6 1
The empirical formula therefore is C₄ H₆ O
Samples of different materials, A and B, have the same mass, but the sample
of A is higher in density. Which statement could explain why this is so?
A. The sample of material A has greater volume than the sample of
material B.
B. The particles that make up material B are more closely packed
together than the particles that make up material A.
C. The particles that make up material A have more mass than the
particles that make up material B.
D. The particles that make up material B have more mass than the
particles that make up material A.
SUBMI
C. The particles that make up material A have more mass than the particles that make up material B.
The correct option is (c) The particles that make up material A have more mass than the particles that make up material B.
A substance containing atoms that are smaller, more massive, and close together will have a higher density. A substance will have a lower density if its larger, lighter atoms are spaced farther apart.The distances between the particles in each state of matter determine how dense solids, liquids, and gases are.Will the density of a material always be the same?Density is an intensive property. This means that regardless of the object's shape, size, or quantity, the density of that substance will always be the same. Even if you cut the object into a million pieces, they would still each have the same density. It is because density in an intensive property of matter.Learn more about Density of a material brainly.com/question/1733081
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What is the total amount of heat released in kilojoules when 112.0 g water at 50.0∘C cools to form ice at −45.0∘C? Use the following values for calculations, as needed.
Properties of Water−−−−−−−−−−−−−−−−−−Specific Heats(∘C)gas=1.84 J/g∘Cliquid=4.184 J/g∘Csolid=2.09 J/g∘C
Heat of VaporizationΔHvap=40.7 kJ/molHeat of FusionΔHfus=6.01 kJ/mol
Answer:
Q = 44.5 kJ
Explanation:
Given that,
Mass of water, m = 112 g
Water at 50.0°C cools to form ice at −45.0°C
We need to find the total amount of heat released. The formula for heat released is given by :
[tex]Q=mc\Delta T[/tex]
c is the specific heat of water, c = 4.184 J/g°C
So,
[tex]Q=112\times 4.184 \times (-45-50)\\\\Q=-44517.76\ J[/tex]
or
Q = -44.5 kJ
So, 44.5 kJ of heat is released.
Arrange the following elements in order of increasing (from smallest to largest) atomic size: K, O, Cs, Se. Explain the reasoning behind your chosen order. Do not simply restate the trend, but rather explain why the trend exists.
Which of the following compounds is likely to make the best conductor when
dissolved in water?
a. SO2
b. C6H1206
c. KBr
d. CO
Answer:
c. KBr .
Explanation:
Hello!
In this case, since electrolytes are substances that are able to carry electric current in the form of electrons via ions, those that are ionic are said to have the greatest capacity to conduct the electricity; in such a way, since SO2, C6H12O6 and CO are non-ionic molecules but covalent, they are not good conductor, therefore the best conductor would be c. KBr as it is an ionic compound due to the electronegativity of the K-Br bond.
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What is the molarity of a solution that contains 25.3 g of NaCl in 111 mL of solution?
-14.6 M
-3.90 M
-0.25 M
-5.52 M
Answer:
"3.90M" if approximate
Explanation:
if u didn't understood why i converted volume from millilitres to litre then refer defination of Molarity.
hope it help:)
An object has a mass of 72 kg. What is its weight?
Answer:Acceleration due to gravity on the moon is 1/6 times as that on the earth and we know that mass is property of the material it always remains same and weight is measure of gravitational force, hence
mass of object on moon is 60kg and weight =60g/6=10×10=100N
Explanation:
6.00 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 26. g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured:
product mass
carbon dioxide 20.31g
water 4.16 g
Use this information to find the molecular formula of X
Answer:
C2H2
Explanation:
Mass of Carbon in CO2[tex]= (12/44) (20.31)[/tex] grams [tex]= 5.54[/tex] gram
Mass of hydrogen in H2O [tex]= (2/18)(4.26)[/tex] grams [tex]= 0.46[/tex] gram
We will calculate the % of C and H in the sample
% C [tex]= (5.54/6) * 100 = 92[/tex]%
% H [tex]= (0.46/6)*100 = 7.7[/tex]%
Number of mole of C [tex]= 92/12 = 7.69[/tex]
Number of mole of H [tex]= 7.67/1 = 7.67[/tex]
Fractional share of C [tex]= 7.69/7.67 = 1[/tex]
Fractional share of H [tex]= 7.67/7.67 = 1[/tex]
Empirical Formula = CH
Empirical Mass [tex]= 12+1 = 13[/tex]
Molecular mass [tex]= 26[/tex]
Molecular Formula – CHn
N [tex]= 26/13 = 2[/tex]
Molecular Formula = C2H2