Qualitative analysis Questions and Answers

How many moles of solute are present in 300.0 mL of a 7.6 M solution of NaOH (aq)? Do NOT include units in your answer. If you round during your calculation, be sure to keep at least three (3) decimal places. Report your answer to one (1) decimal place. Answer:

The heat of combustion of fructose, C6H12O6, is -2812 kJ/mol. If a fresh golden delicious apple weighing 4.21 oz (119 g) contains 16.0 g of fructose, what caloric content does the fructose contribute to the apple? Express your answer in Calories to three significant figures.

1. Using chemical formulas, write out the equations of the three reactions you will do, then balance. 2. Classify the reactions as synthesis, decomposition, single displacement or double displacement. Note: the first reaction is a redox reaction and does not fall into any one of the other four categories. (1) Redox. (2) (3) 3. During reaction 1, a brown gas is produced. What is its formula? 7. Reaction 2 involves combining a solution of sodium hydroxide with a solution of copper (II) nitrate. The sodium hydroxide solution is colorless. a. What color is the copper (II) nitrate solution? b. What species is responsible for this color? How do you know when reaction 3 is complete? A student started with 0.3295 g of copper. The mass of filter paper and copper (II) oxide product was found to be 0.5723 g, and that of the filter paper alone was 0.2568 g. Calculate the percent yield of copper (II) oxide.

1.50 g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 138. g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured: Use this information to find the molecular formula of X.

Compound X has a molar mass of 180.15 g mol and the following composition: element mass % carbon hydrogen 6.71% oxygen 40.00% 53.29% Write the molecular formula of X.

Calculate the mass of gold (III) chloride (Au2Cl6) that contains a million (1.0 × 10^6) chlorine atoms. Be sure your answer has a unit symbol if necessary, and round it to 2 significant digits.

Calculate the number of oxygen atoms in a 60.0 g sample of diphosphorus pentoxide (P₂O5). Be sure your answer has a unit symbol if necessary, and round it to 3 significant digits.

Calculate the number of oxygen atoms in a 80.0 g sample of forsterite (Mg2SiO4). Be sure your answer has a unit symbol if necessary, and round it to 3 significant digits.

You have a solution that is 18.5% (v/v) methyl alcohol. If the bottle contains 1.09 L of solution, what is the volume (V) in milliliters of methyl alcohol? Express your answer with the appropriate units.

Consider the following unbalanced equation: C2H6(g) + O2(g) → CO₂(g) + H₂O(g) Which amount requires more oxygen gas, 2.43 mol C₂H6 or 28.8 g C2H6? HOW DO WE GET THERE? For 28.8 g C2H6: How many moles are present in 28.8 g C₂H6? mol C₂H6

A flask contains 0.015 mol of HCl in 10.0 mL of water. a. What is the molarity of the HCl solution? b. In a titration with NaOH, how many moles of NaOH will be required to reach the end point?

A 6.00 % (m/v) NaCl solution contains 18.2 g of NaCl. What is the total volume (V) of the solution in milliliters? Express your answer with the appropriate units.

For the following reaction, 9.37 grams of glucose (C6H12O6) are allowed to react with 13.6 grams of oxygen gas. glucose (C6H12O6)(s) + oxygen(g) → carbon dioxide(g) + water(l) What is the maximum amount of carbon dioxide that can be formed? What is the FORMULA for the limiting reagent? What amount of the excess reagent remains after the reaction is complete?

Does a reaction occur when aqueous solutions of calcium chloride and ammonium sulfate are combined? yes/no If a reaction does occur, write the net ionic equation.

Does a reaction occur when aqueous solutions of barium nitrate and magnesium sulfate are combined? yes / no If a reaction does occur, write the net ionic equation.

In the photoelectric effect experiment, light shines on a metal and no electrons are emitted from its surface. Which of the following changes might result in electrons emitted from the metal surface? Check all that apply. Use light of the same frequency but with higher intensity (brighter). Use light of a lower wavelength. Use a different metal surface with a metal having lower binding energy. Use light of a lower frequency.

A certain gas is present in a 13.0 L cylinder at 4.0 atm pressure. If the pressure is increased to 8.0 atm, the volume of the gas decreases to 6.5 L. Find the two constants k₁, the initial value of k, and ke, the final value of k, to verify whether the gas obeys Boyle's law. Express your answers to two significant figures separated by a comma.

At 4.00 L, an expandable vessel contains 0.864 mol of oxygen gas. How many liters of oxygen gas must be added at constant temperature and pressure if you need a total of 1.96 mol of oxygen gas in the vessel? Express the volume to three significant figures, and include the appropriate units.

How many grams of Rb are there in a sample of Rb that contains 1.07×10^24 atoms?

When the following solutions are mixed together, what precipitate (if any) will form? Note: Leave the answer blank if no precipitate will form. (Express your answer as a chemical formula.) KCl(aq) + NaNO3(aq) → CaCl₂(aq) + Na3PO4(aq) → NaOH(aq) + Fe2(SO4)3(aq) →

Concentrated hydrochloric acid is an aqueous solution that is 35.00 % HCI. The density of the solution is 1.19 g/mL. What mass of HCI is contained in 0.545 L of solution?

A solution of 0.263 M HCI is added to a buffer system containing 0.50 M acetic acid and 0.50 M sodium acetate. Find the pH of the solution. The K, of acetic acid is 1.8 x 10¹5. (show answer as a decimal to 3 significant digits) pH =

LDL receptors are found only in the heart. None of these responses is correct. found in the nucleus of cells. protein molecules on the surface of cells. easily oxidized. openings in cell membranes through which cholesterol can pass.

A 7.12 x 10-4 mol sample of KOH is dissolved in water to make up 50.0 mL of solution. What is the pH of the solution at 25.0°C? Round the answer to three significant figures. Select the correct answer below: 12.2 1.85 15.85 10.9

Gold is a/an element compound homogeneous mixture heterogeneous mixture

For the following reaction, 27.5 grams of diphosphorus pentoxide are allowed to react with 14.7 grams of water. diphosphorus pentoxide (s) + water (l) -> phosphoric acid (aq) What is the maximum amount of phosphoric acid that can be formed? What is the FORMULA for the limiting reagent? What amount of the excess reagent remains after the reaction is complete?

Balance the following redox reaction in basic solution. Br (aq) + N₂(g) → Br₂()+N₂H₂(aq)

Gaseous methane (CH4) reacts with gaseous oxygen gas (O₂) to produce gaseous carbon dioxide (CO₂) and gaseous water (H₂O). What is the theoretical yield of carbon dioxide formed from the reaction of 3.8 g of methane and 9.2 g of oxygen gas?

Nitrogen monoxide reacts with oxygen to form nitrogen dioxide 2NO+O₂ -> NO2 ΔH = -114.1 kJ/mole a) What is the enthalpy change when 1.25 g of NO are converted completely to NO₂? b) Is this reaction endothermic or exothermic? How do you know?

A sample of neon gas occupies a volume of 6.40 L at 69.0°C and 400. torr. If the volume of the gas sample is increased to 8.99 L, while its temperature is decreased to 3.0°C, the resulting gas pressure will be torr.

Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed antidepressants. SSRIs block the reabsorption of the neurotransmitter serotonin in the brain. Changing the balance of serotonin helps brain cells send and receive chemical messages, which in turn boosts mood. Two SSRI medications are Cipralex (escitalopram, C20 H21 FN2O) and Zoloft (sertraline, C17H17 Cl₂N). Determine the molar masses of Cipralex and Zoloft. Molar mass of Cipralex = Molar mass of Zoloft =

In a coffee cup calorimetry experiment, 28.6 mL of 0.100 M NaOH is added to 50.0 mL of 0.100 MHCI. The temperature of the solution increased by 61.3 °C. Calculate AH, in kJ/mole, for the reaction. Use 1.00 g/ mL as the density of the solution and 4.18 J/g °C as the specific heat capacity. Provide answer to 3 significant figures and do not include the unit. Do not use scientific notation.

Hybrid Orbitals Hybrid orbitals are formed by combining the valence orbitals on an atom. A molecule has sp³ hybridization with 2 lone pairs. The electron pair geometry of this molecule is: The geometry of this molecule is: This molecule will have an approximate bond angle of (If more than one bond angle is possible, separate each with a space.

With a partner or a small group, share ideas about the following topics. Then have each person write a paragraph about one of the topics. 1. What are some changes that a fast-food restaurant might have to make when it opens a franchise in another country? Consider, for example, the food, the people, and the local customs. 2. Why are small, independent retail businesses inclined to disappear when franchise stores open nearby? 3. Many companies are now creating franchises in developing countries. Do you think these franchises help or hurt the economies of these countries? Explain your opinion.

What is the molarity of a NaOH solution if 28.2 mL of a 0.355 M H₂SO4 solution is required to neutralize a 25.0 ml sample of the NaOH solution? Select one: a. 0.801 b. 0.629 c. 125 d. 0.400 e. 0.315

A 12.8 g sample of ethanol (C₂H5OH) is burned in a bomb calorimeter with a heat capacity of 5.65 kJ/°C. Using the information below, determine the final temperature of the calorimeter if the initial temperature is 25.0°C. The molar mass of ethanol is 46.07 g/mol. C₂H5OH(l) + 3 O2(g) → 2 CO₂(g) + 3 H₂O(g) ΔH°rxn = -1235 kJ 85.7°C 53.4°C 74.2°C 111°C 28.1°C

In the following reaction: HCO3(aq) + H₂(aq) → H₂CO3 (aq) + OH (aq) Which of the following statement is true? HCO3 is an acid and H₂CO3 is its conjugate base. H₂O is an acid and HCO3 is its conjugate base. H₂o is an acid and OH is its conjugate base. HCO3 is an acid and OH is its conjugate base. H₂O is an acid and H₂CO3 is its conjugate base.

A sample of gas initially has a volume of 859 mL at 565 K and 2.20 atm. What pressure will the sample have if the volume changes to 268 mL while the temperature is increased to 815 K? 10.2 atm 15.3 atm 1.05 atm 9.83 atm 6.53 atm

Using periodic trends, arrange the following atoms in order of decreasing electronegativity: Highest Lowest Si > Ga>Sr> Cl Cl> Si > Ga> Sr Si > Cl> Ga> Sr Sr> Ga> Si > Cl Sr> Ga> Cl> Si

Here is the discussion forum for chapter 12. In addition to posting an answer the question asked, you are to explain your answer. After posting your response, I was two responses submitted by fellow students. You must make your post before you will be allowed to post your comments. Why are there no base pairs in DNA between adenine and guanine or thymine and cytosine?

If the concentration of reactant X after 37s in a reaction was 0.0090 mol/L and after 80s was 0.0010 mol/L, calculate the average reaction rate. Answer to 5 decimal places in mol/Ls. Leave out units

Use the collision theory to provide an explanation of each of the following (2A each): a. Food spoils more rapidly on a counter than in a refrigerator b. Magnesium metal reacts much more quickly in concentrated HNO3 rather than dilute HNO3 c. Large piles of newspapers burn more quickly than the same mass of wood logs d. Paints and stains often have instructions that they should not be applied below 10°C

In electroplating of chromium, how many grams of chromium should be electrodeposited if you pass 4.60 A current through a solution of 0.180 M CrCl3 for one hour? (atomic weights: Cr 52.00; Cl 35.45 amu) A.2.98 g B.3.12 g C. 0.446 g D.9.06 g E.4.02 g

Determine pH Solution containing 0.610 M HClO2 and 0.215 M LiClO2 if Ka of HClO2 is 6.30 x 10^-4. A PH 3.78 B. PH 8.35 C.PH 3.65 D.PH 5.78 PH 2.75

Determine pH of solution containing 0.210 M C6H7NH3Cl (Kb of C6H7NH2 is 3.50 x 10^-7) A. PH 5.35 B, pH 4.67 C. PH 4.11 D.PH 10.9 E. PH 3.57

Since vanadium can have more than one possible oxidation state, there are several different forms of vanadium oxide. One form of vanadium oxide contains 56% V. What is the name and formula of this compound? Show your work or explain your process.

Very dilute solutions can be measured in parts per billion that is, the number of parts in 1,000,000,000 parts of solution. To be effective, the concentration of digoxin, a drug used to treat congestive heart failure, must be 0.5-2.0 ng/mL. Convert both values to parts per billion (ppb).

How many milliliters of a 1.40 M glucose solution contains each of the following number of moles? a. 0.0740 mol b. 3.60 mol

Propyl acetate (CsH1002; molecular weight = 102.13 g/mol) is a water-soluble ester with a characteristic pear-like odor. A lab technician dissolves 5 g of this ester in enough water to give 250 mL of solution. Calculate the molarity of this solution, showing ALL your work. (2 pts)

The initial volume of a gas cylinder is 750.0 mL. If the pressure of a gas inside the cylinder changes from to, what is the final volume the gas occupies? O2.14 L 3.151 L 0.321 L 1.750 L 0.630 L