its c just took test
Why is charcoal black?
Question options:
Charcoal has a black-colored pigment.
Charcoal reflects black-colored light.
Charcoal absorbs all wavelengths of light that fall on it.
Charcoal reflects all wavelengths of light that fall on it.
Charcoal is black because it absorbs all the wavelengths of light, not reflecting any back to the eye. This is due to its porous structure and numerous carbon atoms.
Explanation:Charcoal is black because it absorbs all wavelengths of light that fall on it, rather than reflecting them. The concept of color perception lies in the range of light that an object can reflect or absorb. When an object absorbs all the colors (wavelengths) of light, it appears black to our eyes. This phenomenon is attributed to the structure of charcoal that is highly porous and contains many carbon atoms, allowing it to effectively absorb the light.Learn more about Absorption of Light here:https://brainly.com/question/29708113
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In the reaction shown above, 2.00 x 10^3 g caco3 produce 1.05 x 10^3 g of cao, what is the percent yield?
What is the square root of 54554? What is the square root of 35654?
how many moles of gas sample are 5.0 L container at 373K and 203kPa
Final answer:
To calculate the number of moles of a gas sample in a 5.0 L container at 373 K and 203 kPa, one uses the Ideal Gas Law. By substituting the appropriate values into the equation and solving for 'n', the calculation yields approximately 0.328 moles of the gas under the specified conditions.
Explanation:
The question asks how many moles of a gas sample are in a 5.0 L container at 373 K and 203 kPa. To find the number of moles of gas, we use the Ideal Gas Law, which is PV = nRT. In this formula, P is the pressure (in kPa), V is the volume (in liters), n is the number of moles, R is the ideal gas constant (8.314 J/(mol·K) or 8.314 L·kPa/(mol·K)), and T is the temperature (in Kelvin).
First, we convert the pressure into kPa since R is given in L·kPa/(mol·K). The pressure is already in kPa. Then, we solve for 'n' (number of moles):
P = 203 kPa
V = 5.0 L
R = 8.314 L·kPa/(mol·K)
T = 373 K
Using the Ideal Gas Law:
n = PV / RT = (203 kPa × 5.0 L) / (8.314 L·kPa/(mol·K) × 373 K)
n = 1015 / 3093.402 = 0.328 mol
Thus, under the given conditions, the 5.0 L container holds approximately 0.328 moles of the gas sample.
Enter the net ionic equation representing solid chromium (iii) hydroxide reacting with nitrous acid. express your answer as a balanced net ionic equation. identify all of the phases in your answer.
Final answer:
The net ionic equation for the reaction between solid chromium(III) hydroxide and nitrous acid is Cr(OH)3(s) + 3 H+(aq) → Cr3+(aq) + 3 H2O(l), after removing the spectator nitrate ions.
Explanation:
The question involves writing a net ionic equation for the reaction between solid chromium(III) hydroxide and nitrous acid. To start, write down the full balanced molecular equation:
Cr(OH)3(s) + 3 HNO2(aq) → Cr(NO3)3(aq) + 3 H2O(l)
Now write the full ionic equation:
Cr(OH)3(s) + 3 H+(aq) + 3 NO2⁻(aq) → Cr3+(aq) + 3 NO2⁻(aq) + 3 H2O(l)
Notice that the nitrate ions (NO2⁻) are present on both sides of the equation and thus are spectator ions. Removing the spectator ions gives us the net ionic equation:
Cr(OH)3(s) + 3 H+ (aq) → Cr3+ (aq) + 3 H2O(l)
It's important to verify that both sides of the equation are balanced with respect to both charge and mass. The equation above satisfies this requirement, with three positive charges on both sides and the same number of each type of atom on each side.
Final answer:
The net ionic equation for the reaction of solid chromium (iii) hydroxide with nitrous acid is Cr(OH)₃(s) + 3 HNO₂(aq) → Cr₃+(aq) + 3 NO₂−(aq) + 3 H₂O(l).
Explanation:
The net ionic equation for the reaction of solid chromium (iii) hydroxide with nitrous acid is:
Cr(OH)₃(s) + 3 HNO₂(aq) → Cr₃+(aq) + 3 NO₂−(aq) + 3 H₂O(l)
First, solid chromium (iii) hydroxide reacts with nitrous acid to form chromium ions, nitrite ions, and water.
In this reaction, the hydroxide ions combine with the hydrogen ions from the acid to produce water, and chromium (iii) hydroxide dissolves to leave behind chromium ions in solution.
Since chromium (iii) hydroxide is a weak base and does not dissociate into ions in its solid state, it is included as a whole compound in the net ionic equation. The nitrite ions and chromium ions remain in solution, indicating a chemical change has occurred.
Bases in solution produce what type of ions?
A. sulfide ions
B. chloride ions
C. hydroxide ions
D. hydronium ions
How many grams are in 2.75 moles of KOH? (molar mass=56.11 g/mol)
Answer: C) 154 g
I did the assignment already, it's correct.
Is bioluminescence an endothermic process bioluminescence an endothermic process or exothermic process?\?
Question 8 4 pts What would be the resulting molarity of a solution made by dissolving 31.3 grams of Ca(OH)2 in enough water to make a 1050-milliliter solution? Show all of the work needed to solve this problem.
Answer : The molarity of the solution is, 0.4028 mole/L
Explanation : Given,
Mass of [tex]Ca(OH)_2[/tex] = 31.3 g
Molar mass of [tex]Ca(OH)_2[/tex] = 74 g/mole
Volume of solution = 1050 ml
Molarity : It is defined as the moles of solute present in one liter of solution.
Formula used :
[tex]Molarity=\frac{\text{Mass of }Ca(OH)_2\times 1000}{\text{Molar mass of }Ca(OH)_2\times \text{volume of solution in ml}}[/tex]
Now put all the given values in this formula, we get:
[tex]Molarity=\frac{31.3g\times 1000}{74g/mole\times 1050ml}=0.4028mole/L[/tex]
Therefore, the molarity of the solution is, 0.4028 mole/L
which element is a noble gas: Ne, Br, or O
Answer:
_+_
Explanation:
how can liquids be separated by density? a. the liquids are absorbed by paper b. the liquids are collected as they evaporate c. the liquids are allowed to separate into layers d. the liquids turn into separate vapors
Answer:C
Explanation:
A large Ka favors the _____.
production of hydronium ions
production of hydroxide ions
reaction of hydronium ions
reaction of hydroxide ions
A rock is thrown 1.8 meters in the air. Find out how fast it was thrown ?
To calculate the initial velocity of a rock thrown 1.8 meters in the air, we use the vertical motion equation, resulting in an initial velocity of approximately 5.94 m/s.
Explanation:To find out how fast a rock was thrown 1.8 meters in the air, we can use the physics of projectile motion and the equations of motion under the influence of gravity. Given that the height reached by the rock is 1.8 meters, we can use the equation for vertical motion:
h = vi2 / (2g),
where h is the maximum height (1.8 meters), vi is the initial velocity we want to calculate, and g is the acceleration due to gravity (9.8 m/s2). Rearranging the formula to solve for the initial velocity gives us:
vi = sqrt(2gh).
Plugging in the values, we get:
vi = sqrt(2 * 9.8 m/s2 * 1.8 m) = sqrt(35.28) ≈ 5.94 m/s.
Thus, the rock was thrown upwards with an initial velocity of approximately 5.94 m/s.
Using the kinematic equation v^2 = u^2 + 2as, the initial velocity (u) at which the rock was thrown into the air is found to be approximately 5.94 m/s.
Explanation:To calculate the initial velocity at which a rock is thrown into the air, we can use the kinematic equations for projectile motion. Since air resistance is negligible, we'll apply the equation for an object under uniform acceleration due to gravity.
The equation we use is v^2 = u^2 + 2as, where:
v is the final velocity (0 m/s at the peak of the throw).u is the initial velocity (which we are looking to find).a is the acceleration due to gravity (-9.8 m/s^2, the negative sign indicates that gravity is acting downwards).s is the displacement (1.8 meters upwards).Rearranging the equation to solve for the initial velocity (u), we get:
u = √(v^2 - 2as)
Plugging in the known values:
u = √(0^2 - 2*(-9.8 m/s^2)*(1.8 m))
u = √(0 + 35.28)
u = √35.28
u = 5.94 m/s
The rock was thrown with an initial velocity of approximately 5.94 m/s.
What volume of a 3.00 M KI stock solution would you use to make 0.195 L of a 1.25 M KI solution?
The volume of the 3.00 M KI stock solution needed to prepare 0.195 L of a 1.25 M KI solution is 81.25 mL.
The student is asking how to calculate the volume of a stock solution needed to make a diluted solution of a different concentration. The problem can be solved using the dilution equation C1V1 = C2V2, where C1 and V1 are the concentration and volume of the stock solution, respectively, and C2 and V2 are the concentration and volume of the diluted solution, respectively. For this particular question:
C1 = 3.00 M (stock solution concentration)
V2 = 0.195 L (volume of the desired diluted solution)
C2 = 1.25 M (desired concentration of the diluted solution)
To find V1, the volume of the stock solution, we rearrange the equation to:
V1 = (C2 * V2) / C1
V1 = (1.25 M * 0.195 L) / 3.00 M
V1 = (0.24375) / 3.00
V1 = 0.08125 L or 81.25 mL
Dextrose 25% 1000 ml was ordered, you have only dextrose 70% solution available. how much of the dextrose 70% solution and sterile water will you use to fill this order?
How many valance electrons (ve) does one atom of carbon have?
a. 8 ve
b. 4 ve
c. 2 ve
d. 1 ve?
How does wearing the headset allow an individual to drive the toy car?
How many grams are in 4.5 moles of lithium oxide?
Why is radon gas dangerous at high levels?
The radon is the decay byproduct of radium which emits alpha rays to convert into the lead or polonium. The alpha particles have less penetration inside the cell than the beta particle or gamma rays and have the more dangerous effect than these other days. In the environment, the high presence of radon enters into the lungs through breathing and start to decay. In their decay, it emits alpha rays, which acts as the carcinogenic agent in the body.
A certain weak acid, HA, has a Ka value of 1.8×10−7.
Part A
Calculate the percent dissociation of HA in a 0.10 M solution.
A hydrate of CuSO4 has a mass of 12.98 g before heating. After heating, the mass of the anhydrous compound is found to be 9.70 g.
Explain how you would determine the formula of the hydrate and then write out the full name of the hydrate.
The solution follows as;
Given:
CuSO4 – 9.70 (weight)
Water / H2O – 12.98 – 9.70 = 3.28 (weight)
Molecular weight of CuSO4 – 160
Molecular weight of H2O – 18
To solve;
= weight of CuSO4 x MW of CuSO4
= 970 / 160
= 328/x*18
= 6x = 18
= x – 3
= CuSO4*3H2O
How much water should be added to 1 gallon of pure antifreeze to obtain a solution that is 75 %75% antifreeze?
This means that you need to add 1 gallon of water to 1 gallon of pure antifreeze to obtain a solution that is 75% antifreeze. To obtain a solution that is 75% antifreeze, you need to add 1 gallon of water to 1 gallon of pure antifreeze.
Explanation:To obtain a solution that is 75% antifreeze, you need to determine how much water should be added to 1 gallon of pure antifreeze.
Let's assume that the final volume of the solution, after adding water, remains at 1 gallon.
The amount of antifreeze in the solution can be calculated using the equation:
Amount of antifreeze = Volume of antifreeze / Total volume of solution
Since the volume of the antifreeze is 1 gallon (given) and the total volume of the solution is also 1 gallon (assuming), we can calculate:
Amount of antifreeze = 1 gallon / 1 gallon = 1
This means that you need to add 1 gallon of water to 1 gallon of pure antifreeze to obtain a solution that is 75% antifreeze.
Explain why most metals are malleable and ductile but ionic crystals are not
Answer:
Metals are malleable due to the layers of atoms which can move over each other. Ionic crystals are made of rigid lattice structures
Explanation:
The molecular structure of metals consists of metallic ions in a sea of de-localized electrons. The ions are closely packed in a regular arrangement. The layers of ions are held together due to the electrostatic forces between the ions and electrons. The layers of ions are not bonded to each other directly, which allows them to move when force is applied. This is why metals are malleable
Ionic crystals are strongly bonded lattice structures with oppositely charged ions strongly attracted to each other. As the ions are bonded directly to each other, the application of a force has the potential to break existing bonds, making the structure brittle.
How does the potential energy of the reactants compare to the potential energy of the products in an exothermic reaction, and where does the energy that is given off come from? Explain your answer in complete sentences. My reactants were Baking Soda and Vinegar.
Answer: Potential energy of products is less than the potential energy of the reactants.
Explanation:
Exothermic reactions are defined as the reactions which releases heat. The release in heat is due to the difference in the potential energy of the reactants and the products.
For these reactions, the potential energy of the products is less than the potential energy of the reactants. Total enthalpy change of the reaction is given by the equation:
[tex]\Delta H_{rxn}=\sum H_{products}-\sum H_{reactants}[/tex]
For exothermic reaction, [tex]\Delta H_{rxn}[/tex] is negative.
For the reaction of baking soda and vinegar, the equation follows:
[tex]NaHCO_3+CH_3COOH\rightarrow CH_3COONa+CO_2+H_2O+\text{ energy}[/tex]
As, the energy is written at the product side, this means that the reaction between baking soda an=d vinegar is an exothermic reaction.
Consider the reaction between 50.0 ml liquid methanol, ch3oh (density 0.850 g/ml), and 22.8 l o2 at 27c and a pressure of 2.00 atm. the products of the reaction are co2(g) and h2o(g). calculate the number of moles of h2o formed if the reaction goes to completion.
To calculate the number of moles of H2O formed, determine the moles of CH3OH involved in the reaction, convert the volume of CH3OH to mass using its density, convert the mass of CH3OH to moles using its molar mass, and use the balanced chemical equation to determine the stoichiometry between CH3OH and H2O.
Explanation:To calculate the number of moles of H2O formed, we first need to determine the number of moles of CH3OH and O2 involved in the reaction.
1. Convert the volume of CH3OH to mass using its density:
Mass of CH3OH = Volume of CH3OH x Density = 50.0 mL x 0.850 g/mL = 42.5 g
2. Convert the mass of CH3OH to moles using its molar mass:
Moles of CH3OH = Mass of CH3OH / Molar mass of CH3OH = 42.5 g / 32.04 g/mol = 1.327 mol
3. Use the balanced chemical equation to determine the stoichiometry between CH3OH and H2O:
1 mol of CH3OH produces 2 mol of H2O
Therefore, 1.327 mol of CH3OH will produce 2 x 1.327 = 2.654 mol of H2O
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Which of the following is a mixture?
sand
silicone
silicon dioxide
carbon dioxide
Which practice is a sustainable method of food production?
A. Using drip irrigation systems to conserve water
B. Allowing chemical pollutants to build up in soil
C. Creating a monoculture crop over large areas
D. Practicing high-density livestock farming
The answers a (apex)
Can you dissolve .35 moles of Potassium Permanganate (KMnO 4 ) into 500 mL of water? _________ Why? / Why not? (please show work)
Yes, you can dissolve 0.35 moles of Potassium Permanganate (KMnO4) into 500 mL of water.
Explanation:To answer whether you can dissolve 0.35 moles of Potassium Permanganate (KMnO4) into 500 mL of water, we need to consider the solubility of the compound. Potassium Permanganate is highly soluble in water, with a solubility of about 7 g per 100 mL of water at room temperature. The molar mass of KMnO4 is 158.034 g/mol, so 0.35 moles would weigh 55.3119 g. Since you have 500 mL of water, which is about 500 g, you can dissolve 55.3119 g of KMnO4 into it.
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Which bond has the greatest ionic character? A) H-Cl B) H-F c) H-O d) H-N
Which of the following represents an ion
4He
Ca
Mg
Na+
Answer:
Na+
Explanation:
Atoms may loose or gain electrons in order to attain octate.
Chemical species obtained after loosing or gaining electrons are called ions.
When an element losses electrons, positively charged ion is formed.
When an element gains electrons, negatively charged ion is formed.
Among the given, only Na+ carry a positive charge, rest are neutral.
Therefore, Na+ is an ion.