General Questions and Answers

When heated, KCIO3 decomposes into KCl and 0₂. 2 KClO3 →2 KCl +30₂ If this reaction produced 44.6 g KCl, how many grams of O₂ were produced?

What is the name of the following ionic molecule: Mg3(PO4)2? Magnesium diphosphate Magnesium phosphate tetraoxide Trimagnesium phosphate Magnesium phosphate Trimagnesium diphosphate

A sample containing 33.42 g of metal pellets is poured into a graduated cylinder initially containing 12.7 mL of water, causing the water level in the cylinder to rise to 21.6 mL. Calculate the density of the metal.

Zinc reacts with hydrochloric acid according to the reaction equation Zn(s) + 2 HCl(aq) --> ZnCl₂ (aq) + H₂(g) How many milliliters of 3.00 M HCl(aq) are required to react with 8.05 g Zn(s)?

10. Lead has a density of 11.4 grams per mL, whereas gold has a density of 19.3 grams per kL If I were to make two identical statues, one out of gold and the other out of lead, which would be heavier

Use the following reaction for questions 1 and 2 HCl(aq) + KOH(aq) → KCl(aq) + H₂O(I) 1) How many moles of KOH would be required to react with 0.250 moles of HCI?

6. (optional) A lead ball has a mass of 5.910 g and a diameter of 10.0 mm. What is the density of lead in grams per cubic centimeter? The volume of a sphere equals 4лr³/3, where л is 3.14, and r is the radius.

Why do the elements in the tubes have to have high voltage electricity run through them before the colored light is emitted? In other words, why don't the cold, un-energized tubes glow? The neutrons need to be excited by energy in the form of light

In the 16 years from 1983 through 1999, a musical performance was performed on a famous street 6607 times. What was the average rate of performances per year? The average rate was performances per year. (Simplify your answer. Round to the nearest whole number as needed.)

19,890,000 (population of Florida) 1.989 × 10^7 1989 x 10^3 19.89 × 10^6 0.1989 × 10^8 1,419,000 (population of Hawaii) 14.19 × 10^5 0.1419 x 10^7 1.419 x 10^6 1419 × 10^3

Rb, I, In. Rank elements from largest to smallest ionization energy. To rank items as equivalent, overlap them.

O, S, Se. Rank elements from largest to smallest ionization energy. To rank items as equivalent, overlap them.

Enter a complete electron configuration for nitrogen. Express your answer in complete form, in order of increasing orbital. For example, 1s²2s² would be entered as 1s^22s^2. Enter a complete electron configuration for chlorine. Express your answer in complete form, in order of increasing orbital. For example, 1s²2s² would be entered as 1s^22s^2.

Propane, C3H8, is a liquid in a pressurized barbecue tank but vaporizes instantly as it flows out of the tank. Calculate the mass of propane that would vaporize as a result absorbing 100.0 kJ of energy. The molar enthalpy of vaporization of propane is 15.7 kJ/mol.

Suppose the mass spectrum of a hypothetical monatomic element X contains a signal at mass number 13 and another of identical height at mass number 15. A. Sketch the mass spectrum. Make sure each axis is properly labeled. B. How many isotopes are present? Why? C. What are the fractional abundances of the isotopes? Why?

Glycerol is a syrupy liquid often used in cosmetics and soaps. A 2.50-L sample of pure glycerol has a mass of 3.15 x 10³ g. What is the density of glycerol in grams per cubic centimeter? Express the density to three significant figures.

Select all that apply Which of the following are examples of mixtures? Select all that apply. Nitrogen gas Tap water Argon Soil Carbon dioxide

What kind of bond is present in HCI? (Use the electronegativity values from the periodic table link to help you answer this question.) A. Valence bond B. lonic bond C. Covalent bond D. Metallic bond

Consider three elements with the following abbreviated electron configurations: X = [Ar]4s^2Y = [Ne]3s^2 3p^4 Z = [Ar]4s^2 3d^10 4p^4 Identify element X as a metal, metalloid, or nonmetal. metal metalloid nonmetal Identify element Y as a metal, metalloid, or nonmetal. metalloid nonmetal metal

Rank the following elements by atomic radius. Rank from largest to smallest atomic radius. To rank items as equivalent, overlap them.

Convert a length of 11.0 m to inches. Express your answer numerically in inches.

In a certain grocery store, strawberries cost $6.88 per pound (6.88 dollars/lb ). What is the cost per ounce? Express your answer numerically to the hundredths place.

Dr. Fried orders 250 mcg Digoxin Elixir by mouth daily for his patient. The patient's apical pulse is 65 bpm. If Digoxin Elixir is dispensed as 0.5 mg/2 mL, how many mL will you give Dr. Fried's patient per dose?

Dr. Velasco prescribes his cancer patient 100 mg of Noxafil oral suspension by mouth daily for a fungal infection. Noxafil comes from the pharmacy as 40 mg/mL. How many mL will you give the patient per dose? (IGNORE significant figures)

Dr. Keppel orders that her patient get 75 mg of Posaconazole by mouth once a day. Posaconazole is dispensed by the pharmacy as 20 mg/2 mL. How many mL will you give Dr. Keppel's patient per dose? (IGNORE significant figures)

Rank the following atoms by number of valence electrons. Rank from most to fewest valence electrons. To rank items as equivalent, overlap them.

Using the chemical equation in question one, calculate the number of moles of carbon dioxide produced by the consumption/production of the following. a. 2.48 mol O₂ b. 21.7 g CH₁ c. 50.6 g H₂O

A sample of a metal has a mass of 14.5 g. When the sample is placed in a graduated cylinder that contains 32.3 mL of water, the volume changes to 36.4 mL. What is the density of the metal? the density cannot be determined from this information 4.1 g/cm³ 2.83 g/cm³ 3.54 g/cm³

How many 4d electrons are in I? Express your answer as an integer. How many 3s electrons are in Mg? Express your answer as an integer.

Suppose a liquid has a specific gravity of 0.877. What is the density of the liquid? 0.877 g/mL 1.14 g/mL 2.28 g/mL the density cannot be determined from this information

How are chemical bonds formed? A. Through removing parts of the nucleus B. Through gaining a core electron C. Through obtaining 10 valence electrons D. Through transferring or sharing electrons

A match is lit and held under a cold piece of metal. The following observations are made: (a) The match burns. (b) The metal gets warmer. (c) Water condenses on the metal. (d) Soot (carbon) is deposited on the metal. Which of these occurrences are due to physical changes, and which are due to chemical changes?

Two beakers contain clear, colorless liquids. When the con- tents of the beakers are mixed a white solid is formed. (a) Is this an example of a chemical or a physical change? (b) What would be the most convenient way to separate the newly formed white solid from the liquid mixture-filtration, dis- tillation, or chromatography.

A sample contains both KBr and KI in unknown quantities. If the sample has a total mass of 7.00 g and contains 1.79 g K, what are the percentages of KBr and KI in the sample by mass? Enter your answers numericaly separated by a comma.

The rock in a particular iron ore deposit contains 82 % Fe2O3 by mass. How many kilograms of the rock must be processed to obtain 1400 kg of iron? Express your answer using two significant figures.

How many oxygen atoms are in each set? five sulfur dioxide molecules Express your answer as an integer.

What is the specific heat of a metal sample if a 85 g sample absorbs 2.3 x 10^-3 MJ of heat and its temperature changes from 25°C to 175°C? Note that the energy given is in megajoules and must be converted to Joules. Answer: _____ J/g °C

Which best distinguishes a substance from a mixture? Mixtures are pure samples of matter. Substances may exist in a homogeneous state. Mixtures are composed of consistent quantities of matter. Properties of substances are consistent from one sample to another.

Silicon-28 contains 14 protons and 14 neutrons. The radius of the nucleus is approximately 3.6 fm, and the radius of the atom is approximately 111 pm. Calculate the volume of the nucleus and the volume of the atom. (Hint: Convert both given radii t m, and then calculate their volumes using the formula for the volume of a sphere, which is V = 4/3πr³.) Express your answers in cubic meters to two significant figures separated by a comma.

A piece of nickel is heated to 107.2 °C. It is then submerged into 235.0 g of water at 22.6 °C that is in a coffee cup calorimeter. The final temperature of the mixture is 28.8 °C. What is the mass of the nickel? Specific heat of nickel is 0.440 J/g°C. Change in temperature for the water = Heat gained by the water (q) = Change in temperature for the nickel = Heat lost by nickel (q) = Mass of nickel = When this mass of nickel is converted to nanograms, what is the exponent (in proper scientific notation)? Give the elemental symbol of nickel.

Choose the correct plural form of the given word: Basis bases basises bassis

A student is investigating the effect of salt on muscle tissues. Which of the following would be considered a reasonable hypothesis? All of the muscles were isolated from the same variety of frog. Salt is more important than sugar for muscles The addition of salt causes the muscles to relax. Observing what occurs when salt is added to the muscles.

What is the type of sensory language used in the following sentence from "A Tornado at Sea" by George Cupples? "The gale still whistled through her spars for two or three hours." Kinesthetic imagery Auditory imagery Olfactory imagery

A pure copper cube has an edge length of 1.28 cm How many copper atoms does it contain? (volume of a cube = (edge length)³; density of copper = 8.96 g/cm³)

A wooden object has a mass of 10.782 g and occupies a volume of 13.72 mL. What is the density of the object determined to an appropriate number of significant figures? 8x 10-¹ g/mL 7.9 x 10-¹ g/mL 7.86 x 10-¹ g/mL 7.859 x 10-1 g/mL 7.8586 x 10-¹ g/mL

Which of these cannot be developed into a narrative draft? Is animal testing necessary? My first project in San Francisco My memories of my father

Match the glassware (equipment) with the best description for its use and/or appearance. Graduated cylinder Erlenmeyer flask Beaker Test tube Crucible

What is the denotative meaning of the word "reticent?" easy-going reserved expansive

You desolve 3mmol of Mg(OH)2 into 300 ml of water. Mg(OH)2 will dissociate into Mg2+ & 2 OH-. How many ml of water must be added to make this sollution to have [OH-] = 1mM? hint: This one is difficult. You need to realize [OH-] is not same as [Mg(OH)2]. So get the concentration of [OH-]. Then, use dilution formula. C1V1=C2V2. Amount of water added must be Vfiinal-Vinitial. 1000ml 3000ml 6000ml 9000ml

Synonyms blabby, chatty, conversational, gabby, garrulous, talkative, motor-mouthed, mouthy, talky Antonyms closemouthed, laconic, reserved, reticent, taciturn, tight-lipped, uncommunicative According to this entry, the word "loquacious" comes from Latin French Turkish