General Questions and Answers

For a 25.0 % m/v MgCl₂ solution. 1. What is the molarity? The GFW for magnesium chloride is 95.21 g. (hint: find the g in 1000 ml, then convert to moles) there are 25.0 g in 100. mL, so there are 250. g in 1000. mL 25.0 g 1000. mL 2. What is the osmolarity? MgCl₂ → Mg¹2 1 mol = + a. 250. b. 100.0 J. 1 k. 6.00 x 10-3 q. 7.65 x 10-10 r. 2.63 2 CH mol L 09 osmoles -X- C. 2 1. 3.60 x 10-2 S. 7.89 d. 30.00 -X- osmoles mol e. 6 f. 24 m. 6.00 x 10-² n. 5 t. 5.26 u. 95.21 mol 8 09 11 11 g. 3 h. 36 0.3.0 x 10-² V. 10¹2 1. 18.0 p. 1.80 x 10-2 W. 109 h M osmoles/L

A quantity of 36.4L of methane gas is heated from 25°C to 88°C at constant pressure. What is its final volume? What law did you use to solve? Make sure to show all work, for partial credit if your answer happens to be incorrect. Equations: P₁ P₂ V₁ V₂ P₁V₁ P₂V₂ P.V₁ = P_V₂ 2-2 2-1/2 2V AV = 2 T₁ T₂ T₁ T₂ T₁ T₂

Show all work! 4. You just got a new job at Tommy's Malt Shop! It is your job to order all the food. To make a cheese burger you need to follow this recipe: 3 Ch + 1 M + 2 B → 1 Ch3MB₂ In your order one box contains 1050 pieces of Ch (cheese), 850 M (meat patties), and 1000 B (buns). -> a. How many total cheese burgers will you be able to make? (SHOW WORK) 1050 ch 1CH3 MB2- 350ch3 MB2 = 10008 x Ich 3 MB2 2-B 3ch b. What is the limiting ingredient (s)? Why? c. What is the excess ingredient (s)? Why?

14 Refer to the chemical equation below to answer your question. Note: [x] means the concentration of x. The reaction is at equilibrium. If H3PO4 is added to the reaction system, what is a possible result? H3PO4 + H₂O → H₂PO4 + H30+

Problem G The % (v/v) of ethanol in Everclear is 90%. Ethanol has a density of 0.789 g/mL and a chemical formula of C₂H,O. (a) Calculate the % (m/v) of ethanol for Everclear. (b) Calculate the M of ethanol for Everclear.

How many microliters of a 856.0 ppm Co²+ stock solution are required to prepare 23.00 mL of a 23.0 ng/μl. Co²+ solution? Significant figures are graded for this problem. Be sure you do not round your answers until the very end of your calculations. V = μL

Lipoprotein complexes carry lipids in the bloodstream. Which of the following lipoproteins carries cholesterol (at least 25% cholesterol by weight)? (Select all that apply.) very-low-density lipoprotein chylomicrons low-density lipoprotein high-density lipoprotein

The end point of a titration was reached after 21.1 mL of 0.050 M disodium EDTA titrant was dispensed into a solution containing the zinc ion. Calculate the moles of disodium EDTA used.

Which two functional groups are in the molecule shown below? Use the terms left and right to distinguish them. H O "The left functional group is a carboxylic acid. The right functional group is an alcohol"

Classify each substance as an atomic element, molecular element, molecular compound, or ionic compound. Atomic element 00 Mn O Molecular element 8 888 Molecular compound CO Ionic compound FeCl,

How many moles of MgCl₂ are needed to make 190 mL of 3.00 M MgCl₂ solution? 0.57 mol 570 mol O 63 mol O 0.016 mol

Hydrogen atoms are excited by a laser to the n = 4 state and then allowed to emit. What is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 01 03 4 5 6 λ= 7 8 Calculate the wavelength of the 41 transition. IT

What is the energy of a photon of electromagnetic radiation with a wavelength of 623.3 nm? (c = 3.00 x 10 m/s, h = 6.63 × 10-34 J-s) YOU MUST WRITE ALL CALCULATIONS OTHERWISE YOU WILL NO BE GRANTED FULL CREDIT O 3.19 x 10-28 J O 3.19 × 10-¹⁹ J O 1.38 x 10-3⁹ J O 4.81 x 10¹4 J 4.13 x 104⁰ J

According to the Star Trek Fifth Interstellar Geophysical Conference Standard version of the periodic table, there are 140 known elements. In what group of the periodic table would you place element 117, "topaline," which is reported to have been discovered on Ganymede in 2021? Group: If the symbol for topaline is To, predict the formula of a compound that would presumably result from the reaction between calcium and topaline, and name the compound. Spelling counts. formula: name:

The next step is to create a conversion factor relating atoms to volume. The structure of Al is shown. The radius of an Al atom is 143.2 pm. What is the distance of the diagonal of the face of the unit cell, in pm? Molar volume of Al: 9.996 cm³/mol

Given: 4AICI3(s) + 302(g) Ⓡ 2Al2O3(s) + 6Cl2(g); DH = -529.0 kJ determine DH for the following thermochemical equation. YOU MUST WRITE ALL CALCULATIONS OTHERWISE YOU WILL NO BE GRANTED FULL CREDIT Cl₂(g) + Al₂O3(s) ⓇAICI3(s) + O₂(g) +529.0 kJ -176.3 kJ +176.3 kJ +264.5 kJ +88.2 kJ

Which describes the burning of fossil fuels? OA. Turbines are used to heat the fuels. OB. Greenhouse gases are released into the atmosphere. OC. The reaction is endothermic. OD. Petroleum is formed because of the heating.

1. Fill in the diagram (with "high" or "low") to show how intermolecular forces influence the volatility, vapor pressure, and boiling point of a substance. volatility is vapor pressure is boiling point is weak PART B-VAPOR PRESSURE GRAPHS (1 pt each, 4 pts total) Use the graph below to answer the following questions. 2. What is the vapor pressure of CHCl3 at 50°C? 4. What is the normal boiling point of CCl4? 5. Which substance has the weakest IMF? Vapor pressure (kPa) 100 3. What is the boiling point of H₂O when the external pressure is 30 kPa? 80 60 40 20 When IMF are... 0 20 40 CHC 60 ca 80 strong volatility is vapor pressure is boiling point is 100 H₂O 101.3 kPa

The amount of energy needed to change a material from a solid to a liquid is called the heat of O vaporization evaporation condensation fusion

5) A standard laboratory preparation of iodine is shown the following balanced equation: 2 Nal + MnO₂ + 2 H₂SO, Na₂SO4 + MnSO4 + 2 H₂O + 1₂ What is the percentage yield of I, if the actual yield of I, was 39.78 g when the amount of Nal used was 62.55 g. = m Please show the percent yield formula calculation here: What is the percent yield?

Binder: Q4 HO 4. ** Chemistry-Law of Conservation of Matter no [U7 - Lesson 5] Na2CrO4 + KCI →> 4310ATT NaCl + K₂CRO4 Uncommon 5. Describe the mole ratio between potassium chloride and sodium chloride: Schools Change Histo

6) Given the following reactions: Fe (s) + Br₂ (g) → 3 FeBr₂ (s) + Br₂ (g) → Fe Brs (S) If each reaction gives an 82% yield, what mass of FesBr, is produced from 1.00g Fe, assuming Br, is in excess? A) 4.81 g B) 3.94 g C) 2.65 g D) 3.23 g E) 2.57 g FeBr₂ (s)

AlBr3 + Li₂CO3 --> LiBr + Al2(CO3)3 Balance the chemical equation and then type in the correct coefficient for each compound. AlBr3 Li₂CO3 LiBr Al2(CO3)3

2 Fe(s) + 0₂ (9) Keq = 1 x 10 at 1000 K 2 FeO (s) CO₂ (g) C(s) + 0₂ (9) Keq=1 x 10-32 at 1000 K The formation of Fe(s) and O₂(g) from FeO (s) is not thermodynamically favorable at room temperature. In an effort to make the process favorable, C (s) is added to the FeO (s) at elevated temperatures. Based on the information above, which of the following gives the value of Keq and the sign of AG" for the reaction represented by the equation below at 1000 K? B 2 FeO (s) + C(s) 2 Fe(s) + CO₂ (9) Keg 1 × 10 38 Keq 1 × 10-38 Keq 1 x 1026 Keg 1 x 102 AG Positive AG Negative AG Positive AG Negative

Find the amount of heat energy needed to convert 400 grams of ice at -38°C to steam at 160°C. 159984 Joules 1284440 Joules 331056 Joules 246840 Joules

Consider these reactions: Reaction 1: H₂(g) + Cl₂(g) → 2HCl(g) Reaction 2: 20F2 (g) → O₂(g) + 2 F2 (g) Reaction 3: N₂(g) +202 (g) → 2NO₂ (g) - Use Reaction 2. How much energy (in kJ) is released when 54.0 g of oxygen difluoride decomposes? Answer: - AH = -184.6 kJ AH = -49.4 kJ AH = +66.4 kJ kJ (enter a positive value)

A chemist must prepare 900.0 mL of potassium hydroxide solution with a pH of 13.70 at 25 °C. He will do this in three steps: • Fill a 900.0 mL volumetric flask about halfway with distilled water. • Weigh out a small amount of solid potassium hydroxide and add it to the flask. . Fill the flask to the mark with distilled water. Calculate the mass of potassium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits.

How does soap work? Soap works by breaking grease molecules into smaller molecules that dissolve in water. Soap works by making water into a nonpolar liquid which grease can dissolve in. none of the above Soap works by having a polar end and a nonpolar end which allows the water and oil to interact indirectly. Soap works by having a polar end which attaches to the grease molecule and polarizes it and turns the grease molecule into another soap molecule. This is a chain reaction.

A chocolate chip cookie contains 12 Calories. Convert this energy into calories. 1 Calorie = 1 kcal = 1000 cal 1cal=4.184 J 1 kJ = 1000 J Make sure to show all work for partial credit if your answer happens to be incorrect.

Which of the following is an example of kinetic energy? a phase change a book in a backpack chemicals sitting on a shelf particles of a gas moving about in random motion

When 2.13 g of a nonelectrolyte solute is dissolved in water to make 615 mL of solution at 25 °C, the solution exerts an osmotic pressure of 879 torr. What is the molar concentration of the solution? concentration: How many mole moles of solute: What is the molar mass of the solute?

Use the scenario to answer the following question. A group of students working in a chemistry lab is planning a procedure to neutralize 25.0mL of 2.0 M hydrochloric acid (strong acid) with 1.0 M potassium hydroxide (strong base). In their procedure they plan on adding an equal volume of the base to the acid. What would be the expected outcome of carrying out this step as planned? The resulting pH will not be able to be determined because the concentrations of the acid and base are not the same. The resulting pH will be greater than 7 because potassium hydroxide is less concentrated than the hydrochloric acid. The resulting pH will be equal to 7 because a strong base will neutralize a strong acid. The resulting pH will be less than 7 because potassium hydroxide is less concentrated than the hydrochloric acid.

Give the formula for the conjugate base of each acid. a. HNO₂ b. NH4 c. H₂02

What mass of propane, C3H8, must be burned in order to produce 76,000 kJ of energy? Circle one: Is this reaction endothermic or exothermic? Additionally, rewrite the thermochemical equation in the other format. C3H8 +502 → 3CO2 + 4H₂O + 2200 kJ

A candy bar contains 250 Calories. How many joules of energy are in this candy bar? 1 Calorie=1 kcal = 1000 cal 1cal=4.184 J 1 kJ=1000 J Make sure to show all work for partial credit if your answer happens to be incorrect.

It takes 487.5 J to heat 25.0 g of an unknown metal from 25°C to 75°C. What is the specific heat of the metal? Q=mx cx AT Make sure to show all work for partial credit if your answer happens to be incorrect.

These two sentences appear in a paragraph: "Sally loves horses." "Sally hates cowboy movies." If you combine these two sentences into one sentence, using the conjunction "yet," your new sentence will have a compound predicate. compound subject. complex predicate. complex subject.

The molecule C₂H₂Cl₂ has three possible Lewis Structures. When a single molecular formula can apply to different molecules with different properties, the molecules are called isomers. Draw Lewis structures for all 3 isomers of C₂H₂Cl₂. Circle any of these isomers which are polar

A patient with respiratory alkalosis has a blood plasma pH of 7.53. What is the [H3O+] of the blood plasma? Express your answer to two significant figures and include the appropriate units.

For the unbalanced equation NaClO3 -> NaCl + 02 how many moles of Og can be obtained from 1.50 mol NaClO3? O2.50 mol O₂ 1.50 mol O₂ 2.25 mol O₂ O3.00 mol O₂

Arrange the following elements in order of decreasing first ionization energy. (Hint: think about half-filled and completely filled orbitals) Highest lonization Energy Be O B C N Lowest lonization Energy

Which of the following would have the highest concentration of [OH-] in solution? HCO3 NO₂ HCI CN H₂S

Read the following chemical equation. Fe(s) + O2(g) → Fe³+ 02- What most likely happens during this reaction? Iron loses three electrons. Iron gains three electrons. Oxygen loses one electron. Oxygen gains one electron.

Isomers must have the same Ochemical structure O Lewis Dot diagram O carbon parent chain O chemical formula

In the reaction between CO and Fe3O4, the theoretical yield in an experiment is calculated to be 47.2 g Fe. When a careless chemistry student carries out the experiment, the actual yield is 35.6 g Fe. Calculate the percentage yield. 75.4% O 24.6% O 50.3% O 37.7% O none of these.

Complete and balance the following neutralization reaction: NaOH(aq) + HC₂H₂O₂(aq) --> What are the products of this reaction before balancing? NaCl and H₂O Na2C₂H3O2 and H₂O NaC₂H3O2 and H₂O NaCl2 and H₂O no reaction

A calorimeter 1. is an indicator of spontaneity. 2. is equal to the molar enthalpy of reac-tion. 3. is only useful in measuring exothermic re-actions. 4. is a dieting aid. 5. is a device used to measure the transfer of heat energy.

For each reaction below: - Assign Oxidation Numbers - Identify which atom/compound is oxidized and which atom/compound is reduced - Identify the oxidizing agent and the reducing agent Underneath each, write the oxidation half reaction and the reduction half reaction. - 2. 2Fe + 3V₂O3 → Fe2O3 + 6VO

A particular sample of vinegar has a pH of 3.20. ▼ Part A If acetic acid is the only acid that vinegar contains (Ka = 1.8 x 10-5), calculate the initial concentration of acetic acid in the vinegar. Express your answer using two significant figures.

An alcohol is 58.80 % C and 9.889 % 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. Submit Show Approach Show Tutor Steps