Answer:
The chemical formula of the unknown ionic compound is Ag₂CO₃.
Explanation:
The method used to identify the ions present in a given solution of an unknown compound is known as qualitative analysis. Specific tests are carried based on the chemical reaction of these ions and the results they give in these reactions, the ions present innthe compound are identified. Some of the results or observations include formation of precipitates on addition of certain reagents, evolution of gases, colour changes, as well as the color changes that are observed in a flame test of a solutionmof these compounds.
In the given question, when testing for cations, a white precipitate is formed when HCl is added to the unknown compound. When the white precipitate is heated in hot water, it does not dissolve.
From the table of observations, both Ag+ and Pb²+ give a white precipitate on addition of HCl but Zn²+ does not. So the cation present is either Ag+ or Pb²+. However, when heated in hot water, the white precipitate does not dissolve as will be observed if Ag+ were the cation present. Thus, the cation is Ag+.
When testing for anions, a white precipitate is formed when Ca(NO3)2 is added to the unknown compound and when HNO3 is added to the precipitate, it dissolves and bubbles are formed.
Now comparing these results with that as observed with CO₃²- and PO₄³-, both form white precipitates on addition of Ca(NO₃)₂, and the precipitate dissolves on addition of HNO₃. However, only CO₃²- dissolves with the production of bubbles when HNO₃ is added. Thus, the anion is CO₃²-.
Therefore, the compound is Ag₂CO₃ which is formed from the cation Ag+ and CO₃²-.
Suppose of potassium acetate is dissolved in of a aqueous solution of ammonium sulfate. Calculate the final molarity of acetate anion in the solution. You can assume the volume of the solution doesn't change when the potassium acetate is dissolved in it. Round your answer to significant digits.
The question is incomplete, the complete question is;
Suppose 0.377g of potassium acetate is dissolved in 250.mL of a 57.0mM aqueous solution of ammonium sulfate.
Calculate the final molarity of acetate anion in the solution. You can assume the volume of the solution doesn't change when the potassium acetate is dissolved in it.
Round your answer to 3 significant digits.
Answer:
0.0152 M
Explanation:
The equation of the reaction is;
2CH3COOK(aq) + (NH4)2SO4(aq)------> K2SO4(aq) + 2CH3COONH4(aq)
Number of moles of potassium acetate = 0.377g/98.15 g/mol = 0.0038 moles
Number of moles of ammonium sulphate = 250/1000L × 57 × 10^-3 = 0.014 moles
2 moles of potassium acetate yields 2 moles of ammonium acetate
Hence;
0.0038 moles of potassium acetate yields 0.0038 moles of ammonium acetate
Also
1 mole of potassium sulphate yields 2 moles of ammonium acetate
0.014 of potassium sulphate yields 0.014 × 2/1 = 0.028 moles of ammonium acetate
So potassium acetate is the limiting reactant.
Since 0.0038 moles of ammonium acetate is produced, the final concentration of potassium acetate is = 0.0038 moles of ammonium acetate/0.25L = 0.0152 M
Hence final concentration of acetate ions =0.0152 M
2x^2+8x-7 solve the equation
Answer:
x = (-4 + √30) / 2, or x = (-4 – √30) / 2
Explanation:
x = (-b ± √b² – 4ac) / 2a →
y = ax² + bx + c
given
y = 2x² + 8x – 7 →
x = (-(8) ± √(8)² – 4(2)(-7)) / 2(2) →
x = (-8 ± √64 + 56) / 4 →
x = (-8 ± √120) / 4 →
x = (-8 ± 2√30) / 4 →
x = (-4 ± √30) / 2 →
x = (-4 + √30) / 2, or x = (-4 – √30) / 2
Which of the following elements is the largest in size
a. O
b. He
c. K
d. H
Answer:
C. K
i took this class before
Answer: The largest element is K
Explanation: As K has the largest radius among O,He and H
Consider the balanced chemical equation below.
2 A ⟶ C + 4 D
How many moles of D would be produced if 6 moles of A were used?
Explanation:
[tex]here \: is \: your \: explanation : - \\ \\ given \: balanced \:equation \: = > \\ \\ 2 A=>C \: + \: 4D \\ \\ by \: this \: equation \: we \: get \: \\ \\ 2 \: moles \: of \: A \: produce \: 4 \: moles \: \\ \\ of \: D \\ \\ hence \: . \: 1 \: mole \: can \: produce \: = 4 \div 2 \\ \\ = > 2 \: moles \: \\ \\ so \: if \: 6 \: moles \: of \: A \: used \: then \: \\ \\ amount \: of \: D \: produced \: = (6 \times 2) \\ \\ = > 12 \: moles \: of \: D \\ \\ \mathcal\blue{ Hope \: it \: helps \: you \: (. ❛ ᴗ ❛.) }[/tex]
The balanced equation for the reaction between aqueous ammonium sulfate and aqueous barium acetate is:________.
A. (NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - Baso, (aq) + 2 NH.C2H2O2 (s).
B. (NH4)2SO3 (aq) + Ba(C2H302)2 (aq) - BaSO3(aq) + NH.C2H3O2 (aq).
C. (NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - BaSO4(s) + 2 NH C2H2O2 (aq).
D. (NH4)2SO4 (aq) + Ba(C2H202)2 (aq) - BaSO4(s) + NHC2H2O2 (aq).
E. NH,SO4 (aq) + BaC2H302 (aq) -- BaSO4(s) + NH4C2H2O2 (aq).
Answer:
(NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - BaSO4(s) + 2 NH4C2H3O2 (aq).
Explanation:
In balancing redox reaction equations, the rule of thumb is that the number of atoms on the left hand side of the reaction equation must be equal to the number of atoms of the same element on the left hand side of the reaction equation.
To ensure this, the correct coefficients are written in front of each of the reactants/products and the number of atoms of each element is counted to ensure that the equation is balanced.
If all these procedures are meticulously carried out, the balanced equation for the reaction between aqueous ammonium sulfate and aqueous barium acetate is:
(NH4)2SO4 (aq) + Ba(C2H302)2 (aq) - BaSO4(s) + 2 NH4C2H3O2 (aq).
Is the following sets of quantum numbers valid? Give suitable reason. n=3,l=2,m=3,s=+1/2
Answer:
The set of quantum numbers is not valid
Explanation:
There are four sets of quantum numbers;
1) Principal quantum number (n) which takes on integer values from n = 1,2,3 .......
2) Azimuthal quantum number (l) which takes on values 1, 2, ....(n - 1)
3) Magnetic quantum numbers (ml) which takes on values from (-l) to (+l)
4) spin quantum number (ms) which takes on values of ±1/2.
From the above, we can see that m can not have a value of 3 when l =2 because m has values between (-l) to (+l). Thus, the sets of quantum numbers is not valid.
Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose (CH1206) and oxygen (O2) gas. Calculate the moles of glucose produced by the reaction of 2.40 mol of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to 3 significant digits.
Answer:
.
Explanation:
A reaction produces 3.0 mol of gas, which occupies 1.46 L. What is the volume of the product when 4.1 mol are produced at constant temperature and pressure?
Answer:
1.99 L
Explanation:
Given that,
A reaction produces 3.0 mol of gas, which occupies 1.46 L.
We need to find the volume of the product when 4.1 mol are produced at constant temperature and pressure.
We know that,
PV = nRT
i.e.
[tex]V\propto n\\\\\dfrac{V_1}{V_2}=\dfrac{n_1}{n_2}\\\\V_2=\dfrac{V_1n_2}{n_1}\\\\V_2=\dfrac{1.46\times 4.1}{3}\\\\V_2=1.99\ L[/tex]
So, the new volume is 1.99 L.
Design an experiment to demonstrate phototropism.
Answer:
Object: To demonstrate phototropism
equipments: A black box, window with light source, a well watered potted plant.
Experiment: A wellwatered potted plant is placed inside a darkened black box that is having a small window on one side. This is called as phototropic chamber. Window is remain closed for a day the plant shows normal growth.
Whereas if window is opened atwo days it will be found that shoot tip bends and grows towards light proving that it is positively phototropic.
Describe how you would prepare your assigned ester from a carboxylic acid and an alcohol. You do not need to include a detailed procedure, but you should include any necessary reagents or catalyst (solvents are not needed).
Answer:
The general preparation of esters( for example ethyl ethanoate) is through a process known as ESTERIFICATION.
Explanation:
The formation of an ester by the reaction between an alkanol and an acid is known as esterification. This reaction is extremely slow and reversible at room temperature, and is catalyzed by a high concentration of hydrogen ions.
In the preparation of one of the simpler esters known as ETHYL ETHANOATE the reactants include ethanol(an alcohol) and glacial ethanoic acid(a carboxylic acid) in the presence of concentrated tetraoxosulphate VI acid as a CATALYST. Note that, a catalyst is any substance that is able to increase the rate of a chemical reaction.
The mixture is warmed in a water bath( hot but not boiling) for about 25 minutes. The mixture is poured into a beaker partially filled with a sodium or calcium chloride to remove interacted ethanol. The ethyl ETHANOATE floats on the mixture as oily globules.
What effect does a high carbon level have on a deep ocean
Explanation:
High carbon concentration in the deep ocean means increased absorption of carbon to the atmosphere resulting to even greater and harmful amounts of carbon in the atmosphere. Therefore we need to keep a close eye of the deep ocean in the quest to monitor and pump out excess carbon from this part of marine life.
Which of the following was NOT explained by Dalton's atomic theory?
A. the Law of Multiple Proportions
B. the difference between elements and compounds
C.?the difference between isotopes of an element
D. the Law of Conservation of Mass
Answer:
A. The law of Multiple Proportion
You’re taking a walk on a warm fall morning. The temperature is about 70 degrees Fahrenheit, and you cannot see a cloud anywhere in the sky. You notice that the ground has no dew on it either. This means the
this means that you are wearing warm clothes in warm temperature .quite easy sir
A mixture is -
A. a pure substance made through chemical processes
B. a pure substance made through physical processes
C.
an impure substance made through chemical processes
D.
an impure substance made through physical processes
Answer:
C
Explanation:
an impure substance made through chemical process
Qual número atômico do ferro?
Answer:
The answer is Iron.
Explanation:
I hope this helps you out. Have a nice day!
Select the statement that correctly describes an endothermic process.
a. The enthalpy change for the process is negative.
b. Heat is lost by the system, but work is done on the system.
c. The enthalpy of the products is higher than that of the reactants.
d. The temperature change of the products is greater than that of the reactants.
e. Heat is released by the system, to the surroundings.
Answer:
C. The enthalpy of the products is higher than that of the reactants
Explanation:
An endothermic process is any process with an increase in the enthalpy of the system
The enthalpy of the products is higher than that of the reactants describes an endothermic process. Therefore, option (C) is correct.
What is the endothermic process?An endothermic process can be described as any thermodynamic process with an increase in the enthalpy H of the system. In such a process, a closed system commonly absorbs thermal energy from its surroundings.
An endothermic reaction leads to an increase in the temperature of the system and a decrease temperature of the surroundings. A physical process, such as the melting of ice cubes is an endothermic process.
Whether a process can take place spontaneously depends not only on the enthalpy change but also on the entropy change and absolute temperature.
An endothermic process commonly needs a favorable entropy increase (∆S > 0) in the system. In an endothermic process, the energy of the products is higher than that of the reactants.
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6ooo kg into quintal
Answer:
60 q
Explanation:
The conversion factor is 100; so 1 quintal = 100 kilograms. In other words, the value in q multiply by 100 to get a value in kg.
g 0.500 L of a solution with a concentration of 0.25 M is needed. To prepare this solution, a stock solution with a concentration of 1.25 M is prepared. What volume of the stock solution is needed to create the desired solution
Answer:
0.1 L
Explanation:
From the question given above, the following data were obtained:
Concentration of stock solution (C₁) = 1.25 M
Volume of diluted solution (V₂) = 0.5 L
Concentration of diluted solution (C₂) = 0.25 M
Volume of stock solution needed solution (V₁) =?
The volume of the stock solution needed can be obtained as follow:
C₁V₁ = C₂V₂
1.25 × V₁ = 0.25 × 0.5
1.25 × V₁ = 0.125
Divide both side by 1.25
V₁ = 0.125 / 1.25
V₁ = 0.1 L
Therefore, the volume of the stock solution needed is 0.1 L
Liquid octane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 10.3 g of octane is mixed with 23. g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
9.36 g
Explanation:
The equation of the reaction is;
C8H18(g) + 25/2 O2(g) ----> 8CO2(g) + 9H2O(g)
Number of moles of octane = 10.3g/ 114 g/mol = 0.09 moles
1 mole of octane yields 9 moles of water
0.09 moles of octane yields 0.09 × 9/1 = 0.81 moles of water
Number of moles of oxygen = 23g/32g/mol = 0.72 moles
12.5 moles of oxygen yields 9 moles of water
0.72 moles of oxygen yields 0.72 × 9/12.5 = 0.52 moles of water
Hence oxygen is the limiting reactant;
Maximum mass of water produced = 0.52 moles of water × 18 g/mol = 9.36 g
Trial 1: Heat 30.0 grams of water at 0 °C to a final temperature of 40.0 °C.
Trial 2: Heat 40.0 grams of water at 10.0 °C to a final temperature of 40.0 °C.
Which statement is true about the experiments? (5 points)
The same amount of heat is absorbed in both the experiments because the product of mass, specific heat capacity, and change in temperature are equal for both.
The same amount of heat is absorbed in both the experiments because the heat absorbed depends only on the final temperature.
The heat absorbed in Trial 2 is about 3,674 J greater than the heat absorbed in Trial 1.
The heat absorbed in Trial 2 is about 5,021 J greater than the heat absorbed in Trial 1.
Answer:
Explanation:
Using the formula below to calculate the heat absorbed in each trial:
Q = m × c × ∆T
Where;
Q = amount of heat absorbed (J)
m = mass of substance (g)
c = specific heat of water (4.184J/g°C)
∆T = change in temperature (°C)
Trial 1: Heat 30.0 grams of water at 0 °C to a final temperature of 40.0 °C.
Q = 30 × 4.184 × (40 - 0)
Q = 30 × 4.184 × 40
Q = 5,020.8J
Trial 2: Heat 40.0 grams of water at 10.0 °C to a final temperature of 40.0 °C.
Answer:
The same amount of heat is absorbed in both the experiments because the product of mass, specific heat capacity, and change in temperature are equal for both.
Explanation:
Explanation:
Using the formula below to calculate the heat absorbed in each trial:
Q = m × c × ∆T
Trial 1: Heat 30.0 grams of water at 0 °C to a final temperature of 40.0 °C.
Q = 30 × 4.184 × (40 - 0)
Q = 30 × 4.184 × 40
Q = 5,020.8J
Trial 2: Heat 40.0 grams of water at 10.0 °C to a final temperature of 40.0 °C.
Q=40*4.184*30
Q=5020.8J
a 150 j of energy is added to a system that does 50 j of work is done.by how m uch will tyhe internal energy of system be raised?
The internal energy of system is raised by 3 times
Draw a Lewis structure for thiocyanic acid, HSCN, adding charges and lone electron pairs to the appropriate atoms.
Answer:
See explanation and image attached
Explanation:
Thiocyanic acid is made made up of hydrogen, sulphur, carbon and nitrogen atoms. Carbon is the central atom in the molecule.
The molecule has a total of sixteen valence electrons as shown in the image attached. There are no formal charges in the structure of the molecule as shown.
The molecule is linear in shape.
Pablo, whose mass is 60 kg, is moving along at a velocity of 8 m/s. How much kinetic energy does he have?
Answer:
1920 Joules
Explanation:
* means multiply
^ means exponent
kinetic energy is in Joules or J
kinetic energy = 1/2 * mass * (velocity)^2
kinetic energy = 1/2 * 60 * (8)^2
kinetic energy = 1/2 * 60 * (8*8)
kinetic energy = 1/2 * 60 * (64)
kinetic energy = 1920 Joules or 1920 J
Answer:
KE = 1920 J
General Formulas and Concepts:
Energy
Kinetic Energy Formula: [tex]\displaystyle KE = \frac{1}{2}mv^2[/tex]
m is mass (in kg)v is velocity (in m/s)Explanation:
Step 1: Define
[Given] m = 60 kg
[Given] v = 8 m/s
Step 2: Find KE
Substitute in variables [Kinetic Energy Formula]: [tex]\displaystyle KE = \frac{1}{2}(60 \ kg)(8 \ m/s)^2[/tex]Evaluate: [tex]\displaystyle KE = 1920 \ J[/tex]Topic: AP Physics 1 Algebra-Based
Unit: Energy
The element antimony has two stable isotopes, antimony-121 with a mass of 120.90 amu and antimony-123 with a mass of 122.90 amu. From the atomic weight of Sb = 121.76 one can conclude that: ________
antimony-123 has the highest percent natural abundance
most antimony atoms have a mass of 121.76 amu
antimony-121 has the highest percent natural abundance
both isotopes have the same percent natural abundance
Answer:
antimony-121 has the highest percent natural abundance
Explanation:
percent natural abundance;
121.76 = 120.90 x + 122.90 (1 - x)
121.76 = 120.90 x + 122.90 - 122.90x
121.76 = -2x + 122.90
121.76 - 122.90 = -2x
x= 121.76 - 122.90/ -2
x= 0.57
Where x and 1 - x refers to the relative abundance of each of the isotopes
Percent natural abundance of antimony-121 = 57 %
Percent natural abundance of antimony-123 = (1 - 0.57) = 43%
Let us remember that isotopy refers to a phenomenon in which atoms of the same element have the same atomic number but different mass numbers. This results from differences in the number of neutrons in atoms of the same element.
We can clearly see that antimony-121 has the highest percent natural abundance.
A sealed vessel initially contains 100 g of chlorine gas and 90 g of hydrogen gas. The two gases undergo reaction to form HCl. Which of the following statements is true?
a. 100 g HCl is produced
b. 190 g HCl is produced
c. less than 90 g HCl is produced
d. between 100 and 190 g of HCl is produced
Answer:
d.
Explanation:
H2 + Cl2 = 2HCL
From the equation 2g hydrogen combine with 71g of chlorine.
So 35.5 g Cl2 combines with 1g of H2
There are 100g of Cl2 so this will, by proportion, react with 100/35.5 g hydrogen.
This is 2.8 g hydrogen so the mass of HCl formed = 102.8 g.
The true statement is that d. between 100 and 190 g of HCl is produced.
How do find the mass of HCL?To find mass of HCL:
H2 + Cl2 = 2HCL
From the equation, 2g of hydrogen combines with 71g of chlorine.
So 35.5 g Cl2 combines with 1g of H2
There are 100g of Cl2 so this will, by proportion, react with 100/35.5 g of hydrogen.
This is 2.8 g hydrogen so the mass of HCl formed = 102.8 g.
Hydrogen chloride may be formed by the direct combination of chlorine (Cl2) gas and hydrogen (H2) gas.
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20.1 cm3 of metal hydroxide (MOH) containing 4.8 g/dm3 react Completely with 23.0 cm3 of the HCL and Containing 3.8g/dm3. Identify the metal of M of MOH
Answer:
A metal M readily forms water-soluble sulphate MSO4, water-insoluble hydroxide M(OH)2 and oxide MO. The oxide and hydroxide are soluble in NaOH. The M is:
Methanoic acid is the simplest carboxylic acid molecule. It has one carbon atom. Draw the structural model for methanoic acid (using C and H).
ANSWER IS ABOVE
THE METHANOIC ACID
Explain why caffeine can be extracted from the tea leaves into hot water and how you extracted the aqueous solution and isolated the crude caffeine.
Answer:
The hot water dissolves the flavor and color components.
Explanation:
Caffeine can be extracted from the tea leaves into hot water because the hot water dissolves the flavor and color components away from the solid vegetable. This is an example of a solid-liquid extraction. We can extracted the aqueous solution and isolated the crude caffeine by converting the components of caffeine into their calcium salts which are insoluble in water. Then the caffeine can be extracted from the water by using methylene chloride.
What happens in a flame test?
A. Electrons are excited to higher energy levels and their emissions
are observed.
B. Impurities in a sample are burned off in the flame until a pure
sample remains
C. Electrons are ejected from atoms when a sample is burned in the
flame.
D. A sample is melted in a flame to determine how much energy was
In a flame test electrons are excited to higher energy levels and their emissions are observed. Therefore, option A is correct.
What is flame test ?The flame test is used to visually identify the identity of an unknown metal or metalloid ion based on the properties color the salt turns in the flame of a bunsen burner.
The color of light emitted depends on the energy emitted by an electron returning to its original state.
The flame's heat converts metal ions into atoms, which become excited and emit visible light. In a flame test electrons are excited to higher energy levels and their emissions are observed.
Thus, option A is correct.
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11th grade chemistry question will mark brainliest
2.50 g of CO2 gas is confined in a rigid cylinder at a pressure
of 4.65 atm. If 0.42 g of gas is released from the cylinder,
what is the new pressure?
Answer:
3.88 atm
Explanation:
We'll begin by calculating the number of mole of CO₂ in each case. This can be obtained as follow:
For 2.50 g of CO₂:
Mass of CO₂ = 2.5 g
Molar mass of CO₂ = 12 + (2×16) = 44 g/mol
Mole of CO₂ =?
Mole = mass / molar mass
Mole of CO₂ = 2.5 / 44
Mole of CO₂ = 0.06 mole
For 0.42 g of CO₂:
Mass of CO₂ = 2.5 g
Molar mass of CO₂ = 44 g/mol
Mole of CO₂ =?
Mole = mass / molar mass
Mole of CO₂ = 0.42 / 44
Mole of CO₂ = 0.010 mole
Finally, we shall determine the new pressure. This can be obtained as follow:
Initial mole (n₁) = 0.06 mole
Initial pressure (P₁) = 4.65 atm
Final mole (n₂) = 0.06 – 0.010 = 0.05 mole
Final pressure (P₂) =?
NOTE: Temperature and volume is constant.
P₁ / n₁ = P₂ / n₂
4.65 / 0.06 = P₂ / 0.05
Cross multiply
0.06 × P₂ = 4.65 × 0.05
0.06 × P₂ = 0.2325
Divide both side by 0.06
P₂ = 0.2325 / 0.06
P₂ = 3.88 atm
Thus, the new pressure is 3.88 atm.