General Questions and Answers

A student sets up the following equation to solve a problem in solution stoichiometry. (The ? stands for a number the student is going to calculate.) Enter the units of the student's answer.

Compound X is composed of 11.1% hydrogen and 88.9% oxygen. 1. What is the empirical formula of Compound X? Compound X has a molecular mass of 18.0 g/mol. 1. What is the molecular formula of Compound X²

What is the percent concentration (m/m) of a KBr solution prepared by combining 15.0 g of KBr with 150. g of water?

The solubility of NaOH is 129 g NaOH/100 g water at 40°C. If a solution contains 70 g NaOH in 50 g of water at 40°C, is the solution saturated or unsaturated?

Thinking maps should serve as the title page for your essay can change as new ideas present themselves are rigid

A bottle of wine contains 9.0% alcohol (v/v). How much alcohol is contained in 175 mL of wine?

Write the formula for a complex formed between Ag+ and NH, with a coordination number of 2. formula: Write the formula for a complex formed between Zn²+ and OH with a coordination number of 4. formula:

Study the following bibliography, and answer the question that follows. Heller, Steven, and Karen Pomeroy. Design Literacy: Understanding Graphic Design.Allen, Thomas B. Vanishing Wildlife of North America. Washington, D.C.: National Geographic Society, 1974. What is wrong with the above bibliography? It is not in alphabetical order. The second line on the second entry is indented. The colons should be semicolons.

Which of the following is an example of prewriting? rough draft and outline rough draft outline

Choose the correct answer. _ is a rigid stance for or against a topic. Argument Blas Feedback

After your thesis statement, you should begin to think about your supporting points choosing a topic brainstorming

The initial flow chart The initial flow chart must have at least three stages: production, transportation and disposal. Each stage needs to include: material resources needed, energy resources needed, and the effects on the ecosystem. Your chart should be easy to follow and include correct scientific vocabulary.

Is each of these an acid (A), a base (B), or a neutral (N) solution? A solution with pH of 10 A solution with pH of 5 Is each of these an acid (A), a base (B), or a neutral (N) solution? A solution with formula H₂CO, A solution with formula CaBr₂ Does th A solution with pH of 7 A solution with pH of 1 A solution with formula KOH A solution with formula HF

Which of the following contains 0.25 mol of aqueous sodium chloride? 500 mL of a 0.5 mol/L solution 500 mL of a 1.0 mol/L solution 500 mL of a 2.0 mol/L solution 500 mL of a 4.0 mol/L solution

Copper roofs on houses form patina (copper carbonates) over the course of years due to the reaction with oxygen, carbon dioxide and water in the air. How does the rate of this reaction change at higher altitudes where atmospheric pressure is lowered?

Balance the chemical equation and determine how many oxygen atoms were produced?

A chemist reacts 74.76 g of B2Br6 and 62.06 g of HNO3 as shown below. B₂Bг6+ HNO3 -> B(NO3)3 + HBr Part a) Calculate the maxium mass of B(NO3)3 that can be produced. Part b) Identify the limiting reactant. Part c) Calculate the maximum mass of HBr that can be produced from this reaction. Part d) When complete, the reaction actually produced 58.77 g of HBr. Calculate the percent yield.

If water is added to 50.0 mL of 1.20 M KCI until the total volume is 150. mL, what is the molarity of the dilute solution? 0.400 M 0.200 M 0.360 M 0.600 M

An irregularly shaped metal is placed in 75.0 mL of water in a 100 mL graduated cylinder. The water level rises to 87.5 mL. If the mass of the metal is 34.712 g, calculate its density. The accepted value for the density of certain metal is 7.87 g/cm³. Calculate the percent error in a laboratory experiment that yields a value of 8.15 g/cm³.

b. Compound X has a molecular mass of 18.0 g/mol. What is the molecular formula of Compound X? c. What is the common name for this compound? d. What is the chemical name for this compound?

How many moles of HCN are produced from 10 moles of O2? 2NH3 + 3O2 +2CH4 → 2HCN + 6H₂O

Consider the following balanced reaction: 2A2+ 3B --> C2 + 2D What is the enthalpy of reaction if the enthalpy of formation of the compounds is given as A2 = 11.84 kJ/mol; B = -15.31 kJ/mol; C2 = 0 kJ/mol; D = 17.54 kJ/mol. Record your answer in scientific notation using 3 significant figures.

Enter your answer in the provided box. How many liters does 67.0 g of O₂ occupy at STP? L

In a "kitchen chemistry" experiment, baking soda is added to vinegar in a flask and a deflated balloon is stretched over the mouth of the flask. Vigorous bubbling is observed, the flask feels colder, and the balloon inflates, as seen in the diagram below. The reaction that occurs is: NaHCO3 (s) + HC₂H3O2 (aq) --> NaC₂H3O2 (aq) + H₂O(l) + CO2(g) When this reaction occurs, heat flows primarily from the _ to the _ When this reaction occurs, work is done _ the system and wsystem is _

The reaction of bromine gas with chlorine gas, shown here, has a Kp value of 7.2. Br₂(g) + Cl₂(g) <--> 2 BrCl(g) If a closed vessel was charged with the two reactants, each at an initial partial pressure of 0.50 atm, what would be the equilibrium partial pressure of BrCl(g)? 0.84 atm 1.4 atm 0.29 atm 1.9 atm 0.57 atm

A flammable hydrocarbon burns in the presence of oxygen to produce gaseous carbon di oxide and water vapor. It contains 10 Hydrogen atoms and 4 Carbon atoms. What is the mass percent of Hydrogen in the given hydrocarbon? A. 20.1% B. I do not know C. 1.73% D. 2.7% E. 17.3%

Which of these does not come under the rules of using quotation marks? Question marks and exclamation points go inside the quotation marks if they are part of the quotation. Quotation marks introduce a restatement of the main clause. Semicolons always go outside quotation marks.

The mineral component of human bone is known as hydroxyapatite which is a naturally occurring mineral form of calcium apatite with the formula Ca3(PO4)3(OH). a. Calculate the molecular weight of the compound and the mass percent of each element.

The element Oxygen (O) is located directly above the element Sulfur (S) in the periodic table of the elements because, compared to Sulfur, Oxygen has An equal number of valence electrons and a lower atomic number An atomic number and atomic mass that are exactly eight units lower An average neutron to proton ration that is significantly higher One less valence electron and also one less proton in its nucleus

Cyclohexane (density = 0.779 g/mL and water are placed in a test tube. After vigorous mixing they separated into two distinguished layers. The top layer contains _ and the bottom layer contains

Which set contains elements written in order of increasing ionization energy? Be < Mg <Ca B<C<N CI<S<P K<I< Po

Which substance is a liquid at room temperature? neon phosphorus potassium mercury

The empirical formula of a compound is CH₂and its molar mass is about 60g. What is its molecular formula? CH2O C4H8O4 C₂H4O2 C₂H6O3

A shop owner wants to paint the walls of his 20 ft by 20 ft shop. The walls are 8 ft high. The paint will cover 400 square feet per gallon. What is the minimum number of gallons of paint that he must purchase? 1 2 3 4

In lab, you perform the above reaction starting with 20.0 L of propane at STP. What volume of Compound X will be produced (assume it is in it's gas phase at STP)? Use the correct number of significant figures in your answer for this part.

The effective nuclear charge of an atom is primarily affected by electron distribution inner electrons nuclear charge outer electrons orbital radial probability

Sodium metal reacts with chlorine gas according to the balanced reaction 2Na+ Cl₂ → 2NaCl If x is the number of moles of NaCl that are produced, then the number of moles of Cl₂ required are x/2 x 2x 4x

What volume, in liters, of 0.40M NaCl contains 0.20 moles of NaCI? 0.0080 0.20 0.50 0.80

What is the approximate percent-by-mass of nitrogen in N₂O4? 15% 30% 47% 88%

Titanium has three common isotopes: 46Ti (45.95 amu), 47Ti (46.95 amu), and 50Ti (49.94 amu). If the average mass of Titanium is 47.90 amu, and 50Ti has an abundance of 45.3%, what are the percent abundances of 46Ti and 47Ti? (3 pts)

How many moles of molecules are in 138 grams of dimethyl ether (C₂H&O)? 5.31 moles 3.00 moles 0.333 moles 0.188 moles

Calculate the average atomic mass of Sulfur if 95% of all Sulfur atoms have a mass of 31.972 amu, 0.76% of all Sulfur atoms have a mass of 32.971 amu, and the remaining percent have a mass of 33.976 amu. (3 pts)

Match the appropriate octahedral crystal-field splitting diagram with the given spin state and metal ion. Metal ion and spin state high-spin Ni³+ low-spin Co³+ Octahedral splitting diagram

Rules state that the members of the Real Estate Commission must be made up of (a) brokers only (b) four licensees and one non-real estate professional (c) a chairman and five other members (d) the director and five other members

consider the following balanced equation. Mg3N₂(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. What is the % yield? 21.2% 50% 75.5% 63.6%

A laser used in DVD players has a wavelength of 405 nm. What is the frequency of this light in hertz (s-¹)? 7.41x 105 s-1 1.35x 10-13 S-1 7.41x 1014 S-1 1.22x 10² S-1

If you are given two pure liquid samples, which measurement is sufficient to determine that the samples are different substances? mass pressure volume density

Which of the complexes or complex ions has geometric (cis or trans) isomers? [Cr(NH3)4Cl₂]+ [Cr(NH3),CI]²+ [Pt(NH3)₂Cl₂] (square planar) [Co(NH3)₂Cl₂12- (tetrahedral)

A dilute solution of CuSO, is blue. If the solution is evaporated to half its original volume. the intensity of the color in the solution will decrease. the intensity of the color in the solution will increase. the color of the solution will disappear the color of the solution will remain the same

In this reaction below, how many moles of Fe₂O3 are needed to react with 2 moles of CO? Fe₂O3+3CO-> 2Fe + 3CO₂