General Questions and Answers

Kacy finds the initial temperature of an ice water mixture to be 0° Celsius, and the temperature of a classroom to be 25° Celsius. She leaves the ice water mixture in the classroom. Which of the following best explains what will happen to the ice water mixture? Thermal energy will transfer from the room to the ice water until thermal equilibrium is reached. Thermal energy will transfer from the ice water to the room until the system reaches 0° Celsius. Thermal energy will transfer from the ice water to the room until thermal equilibrium is reached. Thermal energy will transfer from the room to the ice water until the system reaches 0° Celsius.

Use the balanced equation in the image below. How many moles of ammonia (NH3) will be produced if 2.22 moles of nitrogen (N2) are used? (Assume there is excess hydrogen gas.) SHOW YOUR WORK TO RECEIVE CREDIT. * N₂ + 3H₂ → 2 NH3

For each of the elements listed, and using a periodic table, how many protons, electrons and neutrons does each element have in a normal neutral ground state configuration. a. Chromium b. Vanadium c. Lead d. Barium

Vanadium (V) oxide is decomposed into the elements sodium and chlorine by means of electrical energy. How many grams of Sulfur dioxide gas can be obtained from the production of 5.50 mol V₂O5?

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 equal to 7 because a strong base will neutralize a strong acid. The resulting pH will be greater than 7 because potassium hydroxide is less concentrated than the hydrochloric acid. The resulting pH will be less than 7 because potassium hydroxide is less concentrated than the hydrochloric acid.

How do gas particles respond to an increase in volume? Increase in kinetic energy and increase in temperature Increase in Kinetic energy and decrease in temperature Decrease in kinetic energy and decrease in pressure Increase in temperature and increase in pressure

What is the empirical formula of a compound that is 75% carbon and 25% hydrogen? The molar mass of a sample of this compound is 32 g/mol. What is the molecular formula?

Given the following equation: 2 K₂O₂ (s) + 2 H₂O(1)→ O₂(g) + 4 KOH(aq) How many grams of H₂are needed to produce 0.18 moles of KOH? (molar mass of H₂= 18.0 g/mole) 1.6 grams 2.5 grams 3.2 grams 6.5 grams

According to this chemical reaction, what is the number of grams of Fe produced from 9.40 moles of H₂? Do not include units in your answer. Round to the tenths place or further. Fe3O4 (cr) + 4H₂ (g) - 3 Fe (cr) + 4H₂O (1)

Why are some isotopes radioactive and others are not radioactive? radioactive isotopes have too many or not enough neutrons radioactive isotopes have too many or not enough protons radioactive isotopes have too many or not enough positrons radioactive isotopes have too many or not enough electrons

Which character is the best example of an archetype? A. A gravedigger who enjoys playing online video games all day B. A nice old man who carves ritual masks out of exotic woods C. A grandmother who suddenly decides to run for city council D. A greedy executive who will stop at nothing to increase profits

Water can dissolve many substances because - F. it has a linear molecular shape G. it is polar with a partial charge on each side of its molecule and has a bent molecular structure H. it has the molecular formula H₂O J. it has a nonpolar molecular structure

Substance A is mixed with water and donates 0.4% of its H+ ions. Which of the following BEST describes Substance A? It is a weak acid and a poor conductor of electric current. It is a weak base and a very good conductor of electric current. It is a strong acid and a very good conductor of electric current. It is a strong base and a very poor conductor of electric current.

A sample of argon has a volume of 1.20 L at STP. If the temperature is increased to 23.0°C and the pressure is lowered to 0.800 atm, what will the new volume be, in L?

A molecular cluster is formed from iron atoms and carbon monoxide (CO) molecules. If the molar mass of a cluster is 503.6 g/mol, and its empirical formula is Fe(CO)4, how many iron atoms does the cluster contain? A) 1 B) 2 C) 3 D) 4 E) 5

Which of the following best describes limiting and excess reactants? The amount of product obtained is determined by the excess reactant. The amount of product obtained is determined by the limiting reactant. The amount of product obtained is determined by the reactant with the largest mass. The amount of product obtained is determined by the reactant with the smallest mass.

Below are the reactants of a single replacement (displacement) reaction: 2 NaBr(g) + Cl₂(aq) → Which product(s) will this chemical reaction form? 2 NaBrCl 2 NaCl + Br₂ 2 Na + 2 CIBr 2 Na+ Cl₂Br₂

Potassium chlorate (KCIO3) decomposes into potassium chloride (KCI) and oxygen gas (O₂), as shown in the equation below: KClO3(s) → KCl(s) + O₂(g) Which set of coefficients balances the chemical equation for this reaction? 1, 1,3 2, 2, 2 2,2,3 2, 3, 6

According to this reaction, how many moles of Cu are needed to react with 5.39 moles of AgNO3? Do not include units in your answer. Round to the tenths place or further. Cu + 2 AgNO3 - Cu(NO3)2 + 2 Ag

You begin pouring sodium chloride into a glass of water. For a long time, the sodium chloride just dissolves in the water, but suddenly it begins to pile up at the bottom of the glass. Which statement is true? The sodium chloride has increased the temperature of the water. The sodium chloride has decreased the temperature of the water. The water is unsaturated. The water is saturated.

Identify the type(s) of intermolecular forces that are present in the product that is produced from this reaction. Write the equilibrium-constant expression (Kp) for the given equilibrium reaction, which is taking place in the production of sulfur trioxide. Consider the equilibrium reaction given above. Consider an experiment where 1.25 mol sulfur dioxide gas and 1.25 mol oxygen gas are combined in a 1.00 L flask at 727 °C with a Kp value of 4.13 x 102. Calculate the concentrations of all the reactant(s) and product(s) at equilibrium.

Al2(SO3)3 + 6NaOH - 3Na₂SO3 + 2Al(OH)3 How many grams of sodium sulfite (Na₂SO3) can be made? (HINT: BE SURE TO USE YOUR LIMITING REAGENT FROM THE PREVIOUS QUESTION) Round your answer to 2 decimal places. Do NOT give units in your answer.

A baseball bat hits a baseball with a force of 100 Newtons. What is the force and its direction exerted by the ball on the bat? A. 100 Newtons, same direction B. 100 Newtons, opposite direction C. 200 Newtons, same direction D. 200 Newtons, opposite direction

Write a balanced chemical equation based on the following description: aqueous potassium phosphate reacts with aqueous nickel(II) bromide to produce solid nickel(II) phosphate and aqueous potassium bromide.

Calculate the density of Iron, in g/mL if the mass of 13.55 g and the volume of 6.45 mL. Report your answer to the correct number of significant figures A. 2.10077519 g/mL B. 2.100 g/mL C. 2.10 g/mL D.2.11 g/mL

7.17 grams of aluminum acetate reacts with 3.21 grams of copper (II) phosphate. Predict the products, write the complete reaction equation, balance, and calculate the mass of the aqueous product.

The activity of chymotrypsin using N-acetyl-l-phenylalanine p-nitrophenyl ester as a substrate at pH = 7.0 was monitored spectroscopically in a 1 cm cuvette. What is the concentration of product produced if an absorbance of 0.6 is obtained at 415 nm, given a molar absorptivity of 15,000 L mol¹ cm¹? There is not enough information to calculate the concentration. 40 uM 2.5 nM 9 mM

When 1.491 grams of sucrose (Molar mass 342.3 g/mol) is burned in a bomb calorimeter, the temperature of the calorimeter increases from 22.41°C to 26.63°C. If the heat capacity of the calorimeter is 4.900 kJ/°C, what is the heat of combustion of sucrose, in kJ/mol?

Calculate the theoretical yield in grams All, from the complete reaction of 113 grams 1₂ according to the following balanced chemical equation:

Alpha Emission One example is when a Uranium-238 nucleus decays, it produces a Thorium-234 nucleus and a Helium-4 nucleus. That Helium-4 nucleus is called an alpha particle(a). We use the symbol 4₂He. These particles can be stopped by paper or skin. Beta Emission The second type of radioactive emission is beta particle emission. A beta particle(B) is a fast-moving electron. We use the symbol º.1e. These particles can be stopped by clothes or wood. Gamma Emission The third type of radioactive emission is gamma ray emission. A gamma ray is photon of light that has the symbol oy. This type of radiation is very high energy and dangerous to living (biological) things. It can be stopped by lead or several feet of concrete. 26. Put the different types of emissions in order of weakest to strongest below:

Using the given reactions find the enthalpy for the decomposition of calcium carbonate into calcium oxide, carbon, and oxygen gas in kJ. Given: CaCO3 (s) → Cao (s) + CO₂ (g) C(s) + O₂ (g) → CO₂ (g) A. 215.5 kJ B. 571.6 kJ C. -215.4 kJ CaCO3 (s) CaO (s) + C (s) + O₂ (g) AH = ? kJ D. -571.6 kJ

What mass, in grams, of precipitate will form when 303 g of nickel (II) nitrate reacts with excess rubidium phosphate? You will need a solubility table to correctly answer this question.

Which of the following is correct that represents the dissociation of ionic compound; Na₂SO4(aq). A. Naz (aq) + SO4² (aq) B. Na*(aq) + SO₂² (aq) C. 2Na*(aq) + SO4² (aq) D. Na*(aq) +2SO4² (aq)

A 16.0 gram sample of iron was heated from 0°C to 35.0°C. It absorbed 246.4 Joules of energy as heat. What is the specific heat of this piece of iron? A. 240 J/g°C B. 3.67 J/gºC C. 1.34 J/g °C D. 0.44 J/g °C

KOH(aq) + HC2H30 (aq) →KC2H30 2H³0₂(aq) + H₂O (1) Calculate the molarity (M) of Acetic acid if the volume of acetic acid is 10.00 mL and moles of acetic acid is 0.002622 moles. 0.002622 M 2622 M 0.2622 M 0.0002622 M

How old is the Earth according to most Geologists? 4.6 billion years 4.6 thousand years 600 million years 4.6 million years

The chemical equation used for the experimental determination of iron in an unknown sample is, 5Fe2+ + MnO4 +8H+ +5Fe³+ + Mn2+ + 4H₂O If the experimental data show that 0.0015 mol of MnO4 has been consumed in the reaction, how many mol of iron is in the sample? A. 1.0 mol B. 0.0030 mol C. 0.0075 mol D. 0.015 mol E. 0.00030 mol

A student has a sample of 1.76 moles of fluorine gas that is contained in a 22.1 L container at 256 K. What is the pressure of the sample? The ideal gas constant is 0.0821 L'atm/mol K. Round your answer to the nearest 0.01 and include units.

Which of the following would decrease the rate of solution when dissolving a solid in water? A. Raise the temperature of the solution. B. Crush the solid before mixing. C. Stir the solution after mixing. D. Use a single cube of solid.

What is the formula for barium fluoride ? What is the formula for sodium iodide ? What is the formula for calcium oxide ?

The picture above shows a water wave hitting the beach. Which of the following is true about this process? A. Neither energy nor water is transferred to the shore. B. Water is transferred to the shore, but energy does not travel with the water. C. Energy is transferred from the water to the shore, but the water does not travel with the energy D. As energy transfers from the water to the shore, the water travels with the energy.

Which of the following would increase the rate of dissolution of a solid in a solution? A. Cool the solid and the solution. B. Cool only the solid. C. Dry up the solvent. D. Increase the temperature of the solvent.

A student is studying a sample of neon in a container with a moveable piston (this means the container can change in size). If the sample in the container is initially at a pressure of 765.9 torr when the container has a volume of 76.7 mL, what is the pressure of the gas when the piston is moved so that the volume of the container becomes 131.8 mL? Round your answer to the nearest 0.01 and include units!

What is the formula for the permanganate ion? What is the name for CIO3? What is the formula for the perchlorate ion?

What is the systematic name for the coordination compound, [Cu(NH3)4]SO4.H₂O? A. Tetraamminecopper(II) sulfate monohydrate B. Aqueous Copper(II) sulfate tetraammonia C. Tetraamminecopper(II) sulfate D. Tetraamminecopper sulfate monohydrate E. Tetraamminecopper(1) sulfate monohydrate

According to Arrhenius' definition of base they form a base when dissolved in water they form hydronium ion when dissolved in water they form hydroxide ion when dissolved in water they form an acid when dissolved in water

Human skin emits radiation at a peak value of λ = 8.23 x 10-6 m. What's the frequency of this radiation? (Hint: remember speed of light, c = 3.00 x 10³ m/s) What type of electromagnetic waves are these? How much energy in electron volts (eV) is carried by one quantum of these electromagnetic waves?

An aircraft company is receiving complaints that passengers in their planes are receiving high levels of radiation from the Sun and other background radiation. sources. They respond by posting the following response online: Airline company: All of our aircraft are designed with state-of-the-art aluminum sheeting that blocks all radiation types from all sources. Thus, our passengers are not exposed to any dangerous levels of radiation inside of our aircraft. The Sun and other background sources produce alpha, beta, and gamma radiation, all of which enter Earths atmosphere. Based on all of the information, what statement best evaluates the airline companys claims?/span/p The aluminum sheeting will not be able to block any type of radiation. The airline company has made a correct claim about their aircraft and radiation. The aluminum sheeting will not block the high energy gamma radiation. Aluminum could block the weak background radiation, but not the Sun's radiation.

What is the formula for sodium nitrite ? What is the formula for barium sulfite ?

If you drew magnetic field lines for this bar magnet, which statement would be true? Arrows point away from both north and south. Arrows point away from south and toward north. Arrows point toward both north and south. Arrows point away from north and toward south.