General Questions and Answers

If the pressure is held constant, but the temperature of the gas inside a balloon is increased, what happens the the volume of the balloon? a) the volume decreases b) the change in volume is not predictable c) the volume increases d) the volume does not change

The solubility of Kl is 50 g in 100 g of H2O at 20 °C. If 110 grams of KI are added to 200 grams of H 2O___________. all of the KI will dissolve the solution will be unsaturated the solution will freeze a saturated solution will form the solution will start boiling

What is the correct answer including significant figure for the calculation of a volume (in mL) with measured numbers? (26.40 /16) x 8.02

Which of the following can be cited as a long-term trend that has characterized the history of suffrage in the United States? Elimination of voting restrictions and growing federal control over voting Growing federal control over voting Elimination of voting restrictions

Select the BEST answer from the choices below. When an object is electroplated with copper, the object to be electroplated, such as a steel spoon, is called the ________ redox electrolyte anode cathode

The CO₂ produced through the combustion of coal is categorized as a greenhouse gas. Choose the best description of the greenhouse effect. LT 10-4 a. Greenhouse gases absorb and scatter infrared radiation in the atmosphere. b. Greenhouse gases block visible light from entering the atmosphere. c. Greenhouse gases absorb UV from the sun and emit IR into the atmosphere. d. Greenhouse gases reflect infrared radiation back into space.

What is a positive feature of first-person narration? It is a natural story technique. The narrator cannot be identified. A first person narrator brings immediacy and a sense of life to the story. The first person pronoun "I" is used.

What is the explicit reasoning in the following argument? All of the employees will have a pay rise, because the company has earned twice the last year's profit. The company has earned so much profit. The employees will have a pay rise. The employees earned twice the last year. The company paid twice the profit.

Consider a sample containing 0.670 mol of a substance. How many atoms are in the sample if the substance is iron? iron: How many atoms are in the sample if the substance is titanium? titanium: How many molecules are present in the sample if the substance is benzene, C6H6?

H₂CO(g) reacts with O₂(g) to form CO₂(g) and H₂O(1) according to the following equation. H₂CO(g) + O₂(g) →→→→CO₂(g) + H₂O(1) + 135 kcal Is this reaction endothermic or exothermic? Is energy evolved or absorbed when the reaction takes place? How many kcal of energy is this when 4.68 mol of H₂CO(g) reacts? kcal

If the Kat 25 °C of a weak base is 5.6 x 10-4, the K₂° of the conjugate acid at this temperature is a. 6.4 x 10-10 b.7.3 x 10-9 c. 1.8 x 10-11 d. none of the other answers are correct e. 3.1 x 10-7

Why is mass NOT considered an intensive property? Select the correct answer below: The mass of a substance depends on how much of the substance is present. The mass of a substance is constant as long as the substance is a solid. The mass of a substance changes when a force is applied on it. The mass of a substance is constant, regardless of the amount of substance present.

Amedeo Avogadro (1776-1856), an Italian physicist, contributed to the world of chemistry in many ways. His main contribution, however, was Avogadro's hypothesis, which eventually led to Avogadro's number. Avogadro's number is the number of items in one mole and has a value of Avogadro's number = 6.02 x 1023 We can use Avogadro's number as a conversion factor for moles and atoms, molecules, or formula units using the following ratios: or 6.02×1023 atoms/ 1 mole of atoms 6.02×1023 molecules/1 mole of molecules 6.02x1023 formula units/ 1 mole of substance Calculate the number of molecules in 5.00 moles H₂S. Express your answer numerically in molecules. H₂S molecules Calculate the number of moles of Cl atoms in 3.61x1024 formula units of magnesium chloride, MgCl₂.

Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 6.30 moles of magnesium perchlorate, Mg(ClO4)2. Express the number of moles of Mg, Cl, and O atoms numerically, separated by commas.

One molecule of ozone, O3, contains three oxygen atoms. Similarly, 1 mole of ozone contains 3 moles of oxygen atoms. We can use this mole ratio to create two conversion factors: 3 moles O/1 mole 03 and 1 mole 03/3 moles O Here's how to find the number of moles of oxygen atoms in 2 moles of ozone: 2 moles 03 × 3 moles O/1 mole O = 6 moles O Part A Calculate the number of moles of aluminum, sulfur, and oxygen atoms in 7.00 moles of aluminum sulfate, Al2(SO4)3. Express the number of moles of Al, S, and O atoms numerically, separated by commas.

A student filled a graduated cylinder with water and read the meniscus at 25.8 mL. The student then dropped a solid material into the graduated cylinder and the water level rose to 35.9 mL. If the solid material had a density of 2.99 g/mL, determine the mass of the solid object.

A solution is made using 180.0 mL of isopropanol (density 0.7860 g/ mL) and 275.0 mL of water (density 1.000 g/mL). What is the molality isopropanol in water?

A solution is made using 111.5 g of dimethyl ether (MM = 46.07 g/mol) and 90.0 g of methanol (MM = 32.04 g/mol). What is the mole fraction of the dimethyl ether in the solution?

What is the molality of lithium ions in a 0.302 m solution of Li3PO4 assuming the compound dissociates completely?

To arrive at the correct answer for your lab report, you take one of your numbers from an old lab report. Identify to which of the following your act falls under. A tiny part of the lab report really doesn't matter. The important thing is that you understand what should have happened. You are copying someone else's work without crediting the source; this is plagiarism.

A solution is made using 100.5 g of ethanol (MM = 46.07 g/mol) and 120.0 g of water (MM = 18.02 g/ mol). What is the molality of the ethanol in the solution?

A solution is made using 180.3 g of hexane (MM = 86.18 g/mol) and 200.0 g of octane (MM = 114.2 g/ mol). What is the molality of the hexane in the solution?

Which of the following are true about air pressure in a cold air mass? Click all that apply. air pressure changes more rapidly with altitude the air is more compacted the air is less compacted air pressure changes less rapidly with altitude has lower air pressure aloft his higher air pressure aloft

Consider that the mass of O in the sample must be the difference between the mass of C and H and the mass of the sample. Calculate the amount (mol) O in the sample. 0.00905 mol H₂O formed 0.0181 mol H in sample 0.0136 mol C in sample

DDT, an insecticide harmful to fish, birds, and humans, is produced by the following reaction: 2C6H5 Cl + C2 HOC13 → C14H9 Cl5 + H₂O In a government lab, 1188 g of chlorobenzene is reacted with 478 g of chloral. a. What mass of DDT is formed, assuming 100% yield? Mass= b. Which reactant is limiting? Which is in excess? c. What mass of the excess reactant is left over? g in excess d. If the actual yield of DDT is 268.0 g, what is the percent yield?

The radius of a ball is 1.66 cm and its mass is 54.24 g. Calculate the volume and the density of the ball.

A compound is found to contain 46.68 % nitrogen and 53.32 % oxygen by mass. What is the empirical formula for this compound?

An organic acid is composed of carbon (70.57%), hydrogen (5.93%), and oxygen (23.50%). Its molar mass is 136.15 g/mol. Determine the molecular formula of the compound.

A compound is found to contain 55.39 % boron, 8.280 % hydrogen, and 36.33% chlorine by mass. What is the empirical formula for this compound? To answer the question, enter the elements in the order presented above.

Diana was working on a chemical reaction in a lab. She took a test tube with sodium chloride solution and added few drops of silver nitrate solution. She observed the formation of a white insoluble substance at the bottom of the test tube. She identified the reaction as a combustion reaction synthesis reaction displacement reaction precipitation reaction

Why is paraphrasing too close to the original text, even with citation, considered plagiarism? There are no direct quotation marks to the exact words of the original. By changing a few words, you have changed the author's idea. By not providing the exact words, you are attributing to the author something that's not his or hers.

A compound is found to contain 49.26 % boron, 10.36 % hydrogen, and 40.39 % chlorine by mass. To answer the question, enter the elements in the order presented above. QUESTION 1: Use the References to access important values if needed for this question. The empirical formula for this compound is QUESTION 2: The molar mass for this compound is 87.78 g/mol. The molecular formula for this compound is

Chloroform (density = 1.48 g/mL) and water are placed in a test tube. After vigorous mixing they separated into two distinguished layers. The top layer contains Water and the bottom layer contains

An alcohol is 70.57 % C and 5.935 % H by mass. The rest is oxygen. What is the empirical formula of the alcohol?Enter the elements in the order C, H, and then O.

A compound is found to contain 15.12 % phosphorus, 6.841 % nitrogen, and 78.03% bromine by mass. What is the empirical formula for this compound?

A 11.61 gram sample of an organic compound containing C, H and O is analyzed by combustion analysis and 17.30 grams of CO₂ and 5.314 grams of H₂O are produced. In a separate experiment, the molar mass is found to be 118.1 g/mol. Determine the empirical formula and the molecular formula of the organic compound. Enter the elements in the order C, H, O empirical formula = molecular formula

Suppose you have translated some passages from an article in a foreign language on the Web into English. Which of the following would you do? Copy alongside the original passage in the foreign language. Cite the source because it is similar to taking ideas from other sources. No one would identify, so no need to reference.

A compound is found to contain 73.23 % xenon and 26.77 % oxygen by mass. To answer the question, enter the elements in the order presented above. QUESTION 1: The empirical formula for this compound is QUESTION 2: The molar mass for this compound is 179.3 g/mol. The molecular formula for this compound is

Write the formula for the polyatomic ion in NH4 Cl. A chemical reaction does not occur for this question.

Soccer fields vary in size. A large soccer field is 111 m long and 85.0 m wide. Assume that 1 mequals 3.281 ft. What are its dimensions in feet?

Soccer fields vary in size. A large soccer field is 111 m long and 85.0 m wide. Assume that 1 m equals 3.281 ft. What are its dimensions in feet? length in feet: ft width in feet: ft What are its dimensions in inches? length in inches: in width in inches: in

The recommended daily intake of potassium (K) is 4.725 g. The average raisin contains 3.573 mg K. Fill in the denominators of the fractions, d, and d2, to complete the conversion factors that can be used to convert between grams and milligrams, given that 1 g is equivalent to 1000 mg.

Which of the following compounds would have the highest boiling point? CH3CH₂CH₂CH₂OH CH3CH₂CH₂CH₂CH₂CH3 CH3CH₂CH₂CH₂CH₂OH CH3CH₂CH₂CH₂CH3

Pair each cation on the left with an anion (from given choices) that will form a soluble compound. (Use each anion only once)

As the caterpillar climbs, its potential energy is increasing. What source of energy has been used to effect this change in potential energy?

A substance absorbs 27300 J of heat that raises the temperature of the system by 255 °C. The specific heat capacity of the substance is 0.332 J/g °C. What is the mass of the substance? a) 2.54 g b) 450 g c) 322 g d) 0.33 g

A voltaic cell is constructed that uses the following reaction and operates at 298 K. Zn(s) + Ni²+ (aq)→ Zn²+ (aq) + Ni (s) (i) What is the emf (E° cell) of this cell under standard conditions? (Use the given standard reduction potential table) (ii) What is the emf (Ecell) of this cell when [Ni2+]=3.00 M and [Zn²+]=0.100 M?

Four particles in Figure (a) below can be arranged in 6 different ways as shown in (b) below. (i) How many microstates are there? (ii) Calculated the entropy of this system in (J/K) using the Boltzmann equation, S = kg In W. (here Kg = constant, 1.38x10^-23 J/K) (iii) What is the entropy of a system with a single microstate?

a. Choose the correct name of [Ni(C₂O4)2 (NH3)2 diamminobis(oxalato)nickelate(II) ion diamminotris(oxalato)nickelate(II) diamminobis(carbonato)nickelate(II) ion Odinitrobis(carbonato)nickelate(II) ion b. Choose the correct name of [Co(en)₂Br₂]+. dibromobis(ethylenediamine)cobalt(III) ion bromo(ethylene)cobalt(III) ion dibromobis(ethylene)cobalt(III) ion bromobis(ethylenediamine)cobaltate (II) ion

In the combustion of methanol, 2CH3OH() + 30₂(g) → 2CO2(g) + 4H₂O(g), How many moles of the excess reactant are left over if you react 0.335 moles of methanol with 0.268 moles of oxygen?