Chemistry in Daily Life Questions and Answers

At 448°C, the equilibrium constant for the reaction is 50.5. What concentration of 12 would be found in an equilibrium mixture in which the concentrations of H₂ were 0.450 M and 0.045 M, respectively?

Does a reaction occur when aqueous solutions of chromium(II) sulfate and barium chloride are combined? If a reaction does occur, write the net ionic equation. Use the solubility rules provided in the OWL Preparation Page to determine the solubility of compounds. Be sure to specify states such as (aq) or (s).

Many chromate (CrO4) salts are insoluble, and most have brilliant colors that have led to their being used as pigments. Choose the correct net ionic equation for the reaction of Co³+ with a chromate ion. Co³+ (aq) + CrO4 (aq) → CoC-O4(s) 2Co³+ (aq) + 3CrO4 (aq) → Co₂ (CrO4)3 (8) 2Co³+ (aq) + CrO4 (aq) → Co₂ (C-04)3(S) 2Co³+ (aq) + 3CrO4 (aq) → Co₂ (CrO4)3 (29)

Consider the following compounds. Which is insoluble? Fel2 PbCl₂ LiBr AlBr3 All of these None of these

What is the oxidation number on O in the following compound? Cao (Positive numbers do not need to contain a +) Solubility Rules

Balance the following equation and predict the states: • Remeber to enter 1's for balancing • States of matter options: s, I, aq, g

A cylindrical piece weighs 20 gram. When it is dropped into a graduated cylinder, the volume of water rises from 50.0 ml to 55.5 ml. What is the volume used to find density? a. 105.5 ml b. 55.5 ml c. 50 ml d. 5.5 ml

Ammonia can be produced by reacting nitrogen gas with hydrogen gas. N2 + 3H2 → 2NH3 If 1.40 g of nitrogen and 0.400 g of hydrogen are used, which reactant is in excess and how much remains? How much ammonia can be produced?

What does bolded text mean in the sentence on page 176 "They often had to hold their breath." A) it was necessary to do it B) they were ordered to do it C) they were not allowed to do it D) they were expected to do it

Convert a pressure of 1379 torr to atm.

Write the balanced equation for this reaction (in lowest multiple integers).

Pure silicon, which is needed in the manufacturing of electronic components, may be prepared by heating silicon dioxide (sand) with carbon at high temperatures, releasing carbon monoxide gas. Choose the unbalanced chemical equation for this process. SiO₂ (s) + C(s) → Si(s) + CO(g) SiO2 (s) + CO(s) → Si(s) + CO₂(g) SiO2 (s) + CO2 (s) → Si(s) + CO(g) + O₂(g) SiO2 (s) + C(s) + O₂(g) → SiO₂ (s) + CO(g)

A gas cylinder contains exactly 15 moles of oxygen gas (O₂). How many molecules of oxygen are in the cylinder? 4.01 x 1022 molecules 6.02 x 1023 molecules 9.03 x 1024 molecules 2.89 x 1026 molecules

A medical lab is testing a new anticancer drug on cancer cells. The drug stock solution concentration is 1.5 x 10-9M, and 4.00 mL of this solution will be delivered to a dish containing 2.0 x 105 cancer cells in 5.00 mL of aqueous fluid. What is the ratio of drug molecules to the number of cancer cells in the dish?

A student performing the experiment "Titration of Acetic Acid in Vinegar" got mixed up where to put the solutions. He put the vinegar in the titrator, and the measured amount of NaOH solution in the beaker. He added the phenolphthalein in the beaker containing the NaOH. If he runs the titration with this set-up, what do you expect to happen to his experiment? The solution in the beaker will initially be colorless, and the color changes from colorless to pink at the equivalence point. The experiment will not work because it is not possible to predict the color change at the equivalence point. The experiment will not work because there will be no color change at the equivalence point. The solution in the beaker will initially be pink, and the color changes from pink to colorless at the equivalence point.

When the ideal gas law is arranged as shown below, what property of the gas is being solved for (represented by the X)? Moles Pressure Temperature Volume

A 0.698 mol sample of Xe gas is confined in a 17.4 liter container at 30.6 °C. If the temperature of the gas sample is decreased to 11.3 °C, holding the volume constant, the pressure will decrease because: Choose all that apply. With lower average speeds, on average the molecules hit the walls of the container with less force. At lower temperatures molecules have lower average speeds. As the number of molecule-wall collisions increases, the force per collision decreases. With higher average speeds, the molecules hit the walls of the container more often. None of the Above

A 0.856 mol sample of Kr gas is confined in a 21.9 liter container at 39.2 °C. If the volume of the gas sample is increased to 43.9 L holding the temperature constant, the average force per molecule-wall collision will not enough information to answer the question increase remain the same decrease

Diazirines (H₂CN2) is a class of reactive organic chemical that, when irradiated with ultraviolet light, will form "carbene." Give a plausible Lewis structure of H₂CNN.

A 2 L vessel contains 4 g of Helium and 4 g of H₂ gas at 27°C. After sometime, 50% of the gas having higher average speed is removed. The percentage reduction in total pressure if temperature remains constant is equal to __

Among PbS, CdS, As₂S3, CuS, HgS, Ag₂S, NiS, COS, Bi₂S3, SnS₂, ZnS a is number of black colour sulphide b is number of white colour sulphide c is number of yellow colour sulphide a²-b/c Find the value of

When a single compound breaks up into two or more components, it is called a______reaction ► View Available Hint(s) decomposition combustion combination single replacement

Write a balanced equation for the combination reaction described, using the smallest possible integer coefficients. When hydrogen combines with iodine, hydrogen iodide is formed.

When 7.70 g of hydrocarbon (molar mas = 341.7 g/mol) is burned in a bomb calorimeter, the calorimeter increases in temperature by 2.32°C. If the heat capacity of the bomb calorimeter is 1.356 kJ/°C, what is the heat of combustion for the hydrocarbon, in kJ/mol?

What should be the H-NMR multiplicity for a proton (type A) with 3 different protons (types B, C, and D) in its adjacency? quartet triplet doublet of a triplet doublet of a doublet

Four Fe²+ ions are key components of hemoglobin, the protein that transports oxygen in the blood. If you assume that these ions are 4Fe²+, how many protons and neutrons are present in each nucleus, and how many electrons are present in each ion? protons neutrons electrons

What is the name of the compound with the formula NH₂HCO3 ? What is the name of the compound with the formula NH NO₂ ? What is the name of the compound with the formula (NH4)3PO4?

1) (solution/solvent/solute) Use the correct word in the following sentence: dissolved in makes up a 2) What is the difference between a strong electrolyte and a weak electrolyte? saturated/supersaturated/unsaturated? 3) As the temperature of the solution (increases/decreases) solid in that liquid (increases/decreases) As the temperature of solution (increases/decreases), _the solubility of a that liquid (increases/decreases) the solubility of a gas in

A cube of aluminum at 15.4 °C is submerged into water that is 98.2 °C. In this situation, heat will be transferred from the aluminum to the water. True False

An expandable container contains 1.25 grams of helium. What is its volume (in L) when it has a pressure of 0.955 atm and a temperature of 22°C? Report your answer to the correct number of significant figures. Show your work here or on a separate sheet of paper to receive full credit for your answer.

What does the term "dry" gas pressure refer to when a gas sample is collected over water? Select the correct answer below: Atmospheric pressure Vapor pressure of water Total pressure of the pure gas plus the water vapor pressure Pressure of the pure gas

Which does NOT influence the bond dipole moment? Select the correct answer below: The electronegativity difference between the atoms in the bond. The magnitude of the partial charges on the atoms in the bond. The distance between the atoms in the bond. The bond dissociation energy of the bond.

16.Indicate whether each of the following statements describes primary, secondary, tertiary, or quaternary protein structure: a. Hydrophobic R groups seeking a nonpolar environment move toward the inside of the folded protein. b. An active protein contains four tertiary subunits. c. Valine replaces glutamate in the beta-chain. d. Protein chains of collagen form a triple helix.

How many milliliters of a 5.2 M NaCl solution would be needed to prepare each solution? a. 15 mL of a 0.17 M solution: b. 350 mL of a 0.039 M solution: mL mL

A chemist placed a 10.00 mL sample of HCI in a flask. The HCI was titrated with 0.100 M NaOH. The titration required 22.08 mL of NaOH to reach the equivalence point. What is the molarity of the HCI sample? 0.0221 M 0.00221 M 0.0453 M 0.221 M

Be sure to answer all parts. How many milliliters of a 4.8 M NaCl solution would be needed to prepare each solution? a. 85 mL of a 2.5 M solution: b. 170 mL of a 0.75 M solution: mL mL

A cough medicine contains 0.20% (w/v) dextromethorphan, a cough suppressant, and 2.5% (w/v) guaifenisin, an expectorant. How many milligrams of each drug would you obtain from 2.0 tsp of cough syrup? (1 tsp = 4.93 mL) mg dextromethorphan mg guaifenisin

Automobile air bags use the decomposition of sodium azide as their source of gas for rapid inflation: 2NaN3 (s)→ 2Na (s) + 3N₂ (g). What mass (g) of NaN3 is required to provide 40.0 L of N₂ at 25.0 °C and 890 torr?

What are the correct units of molarity. mol/L g/L L/mol g/mol

Calculate the value of [OH-] from the given [H3O+] and label the solution as acidic or basic. a. 4.6 × 10-3 M ) b. 1.7 × 10-12 M

Be sure to answer all parts. Calculate the formula weight and molar mass of the following biologically active compound. C16H16CINO2S (Plavix), a drug used to treat coronary artery disease amu, g/mol

Be sure to answer all parts. How many moles of NaCl are contained in each volume of aqueous NaCl solution? a. 7.7 L of a 2.9 M solution mol NaCl b. 82 mL of a 5.4 M solution mol NaCl

What is the weight/volume percent concentration using the given amount of solute and total volume of solution? 50.0 g of LiCl in 850 mL of solution: % (w/v) LICI

Which represents the greatest mass of sulfur? 1 gram of sulfur 0.5 mole of sulfur 1 molecule of sulfur 6.02 x 1023 atoms of sulfur How many moles are in 1.204 x 1024 molecules of CO? 2 moles 6.02 moles 5 grams 1.2 moles

How hot must the air in a balloon be heated if initially it has a volume of 700. L at 20°C and the final volume must be 1,360. L? The balloon is sealed so that the pressure and number of air particles are constant. K

Points 1 Identify the property of ionic compounds. Insoluble in water. Brittle Low melting point. Low boiling point.

Be sure to answer all parts. Calculate the number of grams contained in each of the following number of moles. Report your answer with the appropriate number of significant figures. a. 0.150 mol of NaCl (sodium chloride) b. 6.20 mol of C₂H4 (ethylene) g

Which of the following lists the relative strengths of the fundamental forces from strongest to weakest? A. Strong nuclear force, weak nuclear force, gravitational force, electrostatic force B. Gravitational force, strong nuclear force, electrostatic force, weak nuclear force C. Electrostatic force, gravitational force, weak nuclear force, strong nuclear force D. Strong nuclear force, electrostatic force, weak nuclear force, gravitational force

Which statement describes the potential energy diagram of an exothermic reaction? A. The potential energy of the products is greater than the potential energy of the reactants. B. The activation energy of the reactants is greater than the activation energy of the products. C. The potential energy of the reactants is greater than the potential energy of the products. D. The potential energy of the products is equal to the potential energy of the reactants.

Question 2 of 25 How can an unknown ΔHreaction be determined using Hess's law? A. The free energy of the reaction is used to determine the AH for the reaction. B. The unknown ΔHreaction is determined after the reaction is run in a calorimeter. C. The reaction is repeated at different temperatures to determine the ΔHreaction- D. Enthalpies from reaction steps are added to determine an unknown AHreaction