General Questions and Answers

What is the final temperature when 10.0 grams of water at 25.0 °C absorbs 50.0 calories of heat energy? specific heat of water = 1.00 cal/g °C) 20.0 °C 23.8 °C 30.0 °C 50.0 °C

The number of atoms in 0.50 mole of Br₂ is approximately 1.5x10²9 3.0x10²3 6.0x10²3 12x1023

Arrange the elements according to first ionization energy. Highest ionization energy Lowest ionization energy Ge C Sn Si

A measurement of the mass of an object was made three times and gave values of 9.6g, 9.8g, and 10.3g. What is the best value to report as the mass, in grams, of this object? 9.7 9.8 9.9 10.0

Three grams of a salt were dissolved in 2 liters of water. In order to make 5 liters of a solution of the same concentration, how many grams of salt must be used? 3.3 6.0 7.5 15

What is the molar mass (molecular weight) of the compound C₂H4O₂? 29 32 44 60

What is the symbol of the atom with the electron configuration 1s²2s²2p6 3s²3p3? N O P S

At 298 K, the Henry's Law constant for oxygen is 0.00130M/atm. Air is 21.0% oxygent. A. At 298 K, what is the solubility of oxygen in water exposed to air in 1.00atm? B. At 298K, what is the solubility of oxygen in water exposed to air at 0.892atm? C. If atmospheris pressure suddenly changes from 1.00 atm to 0.892 atm at 298 K, how much oxygen will be released from 5.40 L of water in an unsealed container? Reminder: M = kHP Edit Format Table

Which neutral atom has six valence electrons? Mg (atomic number 12) Si (atomic number 14) P (atomic number 15) S (atomic number 16)

Write the net ionic equation for the reaction of lead(II) nitrate and sodium iodide. Pb(NO)3(aq) + 2Nal(aq) --> Pbl₂(s) + 2NaNO₂(aq) Pb²+(aq) + 2Nal(aq) → Pbl₂(s) + 2Na(aq) Pb²+(aq) + 2I- (aq) → Pbl₂(s) Pb²+(aq) + 2I¯(aq) → Pb²+(s) + 2I- (aq)

You have three solutions of nickel complex ions: one is blue, one is violet, and one is green. Match the complex ion with the correct solution color. Blue [Ni(en)]2+ Violet [Ni(H₂O)]²+ Answer Bank Green [Ni(NH3)6]2+

As a substance was heated, the intermolecular forces could no longer hold molecules rigidly together, and the molecules began to move randomly in relation to one another. Which statement most accurately describes what happened to this substance? It changed from a solid to a liquid It changed from a liquid to a solid It changed from a gas to a liquid It changed from a liquid to agas

consider the following balanced equation. Mg₂N₂(s) + 6 H₂O(l) → 3 Mg(OH)2 (s) + 2 NH3(g) When 100.g Mg3N₂ reacts with 75.0 g H₂O, 15.0g of NH3 is obtained. Which of the following is the limiting reactant? Mg3N2 Mg(OH)₂ NH₂

How many moles of nitrate ions are present in 1.0L of a 0.02M AI(NO3)3 solution? 0.02 0.03 0.06 0.08

How many grams of NaOH (MW = 40g) are present in 0.200 L of 0.25 M solution? 0.05 2 10 50

If you have not yet used your data to make a solubility curve graph, look at the graph provided in the video and Identify the label of the vertical (y) axis and the label of the horizontal (x) axis)

70. The only natural abundances of Boron are B-10 with a mass of 10.013 amu, and B-11 with a mass of 11.009 amu. What are their abundances?

Soap molecules have a polar "head" and a non-polar "tail". How does that help explain why soap is so good at cleaning dirty clothes?

The distance a car skidded during an accident was measured in two parts and found to be 273.15 cm + 21 cm. The total distance should be reported as 294 cm 294.15 cm 294.2 cm 290 cm

Groups of elements have similar atomic mass number of isotopes physical properties valence electrons

Given 35CI-, the correct values of protons, neutron and electrons are 17 protons, 18 neutrons, 18 electrons 17 protons, 17 neutrons, 17 electrons 17 protons, 16 neutrons, 18 electrons 18 protons, 17 neutrons, 16 electrons

Which element has the lowest first ionization energy? Na CI K Br

Calculate the molarity of NaCl in a 0.550 m solution of NaCl in water. Assume that the solution density is 1.03 g/mL.

How can you tell if you are calculating a mole problem; a stoichiometry problem?

Use the following balanced equation to answer the following problems: C5H12 + 8O2 5CO2 + 6H₂O i) When 2.5 moles of oxygen gas react completely with pentane, how many moles of carbon dioxide are produced? ii) How many grams of pentane gas are needed to completely react with 348.5 grams of oxygen?

Magnesium has 3 naturally occurring isotopes: Magnesium-24, Magnesium-25, and Magnesium-26. They have masses 23.985042 amu, 24.985837 amu, and 25.982593 amu, respectively. If 78.99% of all Magnesium is Magnesium-24, what are the abundances of Magnesium-25 and Magnesium-26?

1 mol = 22.4 L 1 mol = 6.02 x 1023 representative particles 1 mol = g (molar mass) 30. Know how to perform mole conversions using moles, grams, and representative particles. a. What is a representative particle? What is the name of the representative particle for the ionic compound? The covalent compound? An element? b. How many representative particles are in a 53.79 gram sample of SrCO3? C. How many moles of AlF3 are in a 10.0 gram sample of AlF3? d. How many grams of SO₂ are in a 0.65 mole sample of SO₂? e. How many moles of copper atoms in 75 g of Cu? f. In a sample with 17.0 grams of water, how many molecules of water are present?

Compare and contrast the behavior of an electrolyte solution and a non-electrolyte solution.

A burner was designed to use LPG whose volumetric composition is propane 60% and butane 40%, currently this burner must use C.N. (methane 100%). Find the diameter ratio between the NG injector and the fuel injector. LPG if you want to keep constant the power in the burner and the pressure of feed is the same for both gases.

Write out the proper formulas of the reactants, predict the products, when necessary, for the reaction, balance the reaction and identify the type of reaction. If the reaction is single replacement tell if the reaction is going to happen. a. silver chlorate reacts with lithium to produce......

Classify each of the following particulate level illustrations as a representation of either a pure substance or a mixture. pure substance mixture

When calcium reacts with fluorine to form an ionic compound, each metal atom loses _ electron(s) and each nonmetal atom gains _ electron(s). There must be _ calcium atom(s) for every _ fluorine atom(s) in the reaction.

Explain how you would make 1.5 L Copper (1) sulfate solution that is 2.0M. V

b. Zinc nitrite reacts with potassium phosphate to create....... C. Tetracarbon decahydride reacts with oxygen to produce carbon dioxide and water d. Iron (III) hydroxide when heated creates iron (III) oxide and water e. Magnesium metal reacts with chlorine to produce magnesium chloride f. NaNO3 + CaCO3 → g. Au + CuCl2 →

A _ spectrometer can also be used to study in detail about the composition of a certain material based on its emitted spectral lines. prism photo absorption emission

FePO4 + Na₂SO4 → Fe₂(SO4)3 + Na3PO4 a. Suppose that Joey ran the reaction above with 25 grams of FePO4 and excess Na₂SO4. What is the theoretical yield of Fe₂(SO4)3 that will be produced? b. If 18.5 g Fe₂(SO4)3 are produced, what is the percent yield? c. Suppose that Bobby runs the same reaction and produces 16 g of Fe₂(SO4)3. Who did a better job running the experiment? Explain.

1. If 20.0 grams of magnesium react with 15.0 grams hydrochloric acid, how many grams of magnesium chloride are produced? 2. How many grams of carbon dioxide are produced if 45.0 grams of sodium hydrogen carbonate reacts with 40.0 grams of acetic acid?

A solution of 3.6 g of NaOH (a strong base) is added to enough water to create a volume of 2.6 L a. What is the pOH of the solution? b. What is the pH of the solution? c. Using the ion product concentration of water (Kw) determine the hydronium ion concentration of this solution?

Draw Lewis dot structures for these simple compounds listed below. i. Br2 ii. O2 iii. N₂ iv. CH4 V. NH3 vi. H₂O vii. HF

If 144g of carbon and 12g of hydrogen gas are fully reacted, what mass of benzene (C6H6) will form? 6C(s) + 3H2(g) --> C6H6) 276g 132g 78g 68g 156g

What amount of heat energy would be necessary to raise the temperature of 100 g of water at room temperature (25°C) to the boiling point (100°C)? The specific heat of water is 1.0 cal/g °C. 7500 cal 750 cal 100 cal 75 cal

Complete and balance the following neutralization reactions HBr + Ca(OH)₂ H3PO4 + Mg(OH)₂

Undergoing moderate activity, an average person will generate about 350 kJ of heat per hour. Using the heat of combustion of palmitic acid (ΔH= -9977.6 kJ/mol) as an approximate value for fatty substances, estimate how many grams of fat would be required per day to sustain this level, if all were burned for heat.

If a person has 629mL of a 4.2M KCI solution. How many moles of KCI would be in the solution? (1000mL=1L) Round to two decimal places.

Suppose you are using phenolphthalein as an indicator for a titration. You start with a flask of base and add the phenolphthalein. Then you add acid until the endpoint is reached. What color is the indicator in the base? What color are you looking for to indicate the endpoint? Explain why a titration is useful:

How much heat is absorbed by 2.50 x 102 g of water and the 450. g Al can (CA1 is 0.900 J/g °C) when they are heated from 10.0 °C to 85.0 °C? (ans. 1.09 x 105 J)

You have 45.6 mL of 10.1 M HBr. You need to use Mg(OH)2 to neutralize it. How many grams of Mg(OH)2 are necessary? Step 1: (a) Write the chemical reaction. (b) Check the subscripts for each new compound. (c) Balance the equation (check the big numbers in front of each compound). Step 2: Determine how many moles of HBr you have. (Hint: M = moles/liter) Step 3: Use the chemical reaction (recipe) to determine how many moles of Mg(OH)2 you need. Step 4: Use the Periodic Table to determine how many grams of Mg(OH)2 you need.

Which of the following are exothermic processes? 1. Combustion of methane 2. Explosion of T.N.T 3. Fusion 4. Melting 2 and 4 2 and 3 1 and 4

Identify the incorrect statement from the following. Increase in temperature, increases the rate of the reaction Stirring decreases the frequency of interaction between the reactants Increase in surface of the reactants, increases the rate of the reaction Increase in pressure of the reactants, increases the rate of the reaction

The burning of 5.08 g benzene (C6H6) releases enough heat to raise the temperature of 5.0 kg of water from 10.1 °C to 19.6 °C. Calculate the molar heat of combustion of benzene. (ans.: -3.1 x 103 kJ/mol C6H6)