chemistry stuff

Select the correct formula for determining percent composition by mass (where E is any element).

%E = mass of E / mass of sample x 100%

Choose the word below that best completes the following sentence: when an ionic solid dissolves in water, the ions that make up the solid ______ and the ions interact with water molecules.

dissociate

- The compound MgCl2 will be a (solid/liquid/gas) _____ at room temperature because it is a(an) (ionic/molecular) _______ compound.

solid, ionic

A molecular compound could contain which of the following atoms?

- C, N, Cl, H,

A molecular compound could contain which of the following atoms?

- N, Cl, C, H

How many moles are NaCl are present in a sample of NaCl with a mass of 84.2 grams?

1.44 moles

How many moles of acetone (C3H6O) are rpesent in a sample of acetone with a mass of 90.2 grams?

1.55 moles

The element phosphorus will form an ion with a charge of:

3-

Main-Group Elements

Groups 1, 2, and 13-18

Inner-Transition Elements

Lanthanides and Actinides

Polyatomic ions are ions that contain two or more ____.

atoms

Dry ice (solid CO2) is a(n) __________ compound. It is relatively _____ solid.

molecular, soft

- molecular compounds - ionic compounds

- low boiling points - high boiling points

Determine the mass of calcium in a 535-mg tablet of calcium carbonate. Calcium carboante is 40.0% calcium by mass.

214 mg

A bulb connected to a battery through a solution of ethanol (CH3CH2OH) does not light up; ethanol is a ___ electrolyte. A bulb connected through a solution of calcium chloride (CaCl2) lights up brightly; calcium chloride is a ______ electrolyte.

non, strong.

What is the mass of a 2.16-mol sample of HNO3?

136 g

Which of the compounds below are molecular compounds?

- CH4, HC2H3O2, CO2

What is the name of the N3- anion?

Nitride - Main-group element anions are named using the fire part of the element's name (nltr-) and -idea as an added suffix. Nitrogen's ionic form is called nitride.

The densities of ionic compounds are (higher/lower) ________ than the densities of molecular compounds.

higher

An ionic compound contains the following

- a positively charged cation - a negatively charged anion - a balance of positive and negative charges

- nonelectrolyte - strong electrolyte - weak electrolyte

- a solution of glucose - a solution of potassium chloride - a solution of sulfurous acid

ZnCO3

- contains a metal cation with a polyatomic anion

NaBr

- contains a monoatomic anion and cation

(NH4)3PO4

- contains a polyatomic anion and polyatomic cation

- Solid sodium chloride, NaCl - Pure liquid water, H2O - Aqueous solution of sodium chloride, NaCl

- (s) - (l) - (aq)

Which of the following relationships is the correct representation of Avogrado's number?

- 1 mole of helium - 6.022 x 10^23 helium atoms.

Select all the statements that correctly describe elements.

- An element is a type of pure substance. - Elemants can be converted into more complex substancse through a chemical reaction with other substances. - An element is a substance that cannot be broken down into simpler substances.

Select all of the following that correctly describe percent composition by mass.

- It is the ratio of the mass of an element to the mass of the sample, multiplied by 100. - It is constant no matter what the size.

Select all the statements that correctly describe matter.

- Matter is anything that occupies spaces and has mass. - Matter can include both large objects and small objects.

Select all the statements that correctly describe molecules.

- Molecules are made up of two or more atoms bound together in a discrete arrangement. - Some molecules are formed by the combiantion of atoms of only one element.

Which of the following are binary molecular compounds?

- NH3, H2O

Match the coorect molar mass with each compound. - 46.01 g/mol - 28.01 g/mol - 32.05 g/mol

- NO2 - CO - N2H4

Describe the notiation used for writing an element symbol.

- The first letter of an element symbol is uppercase, and the second letter, if present, is lowercase. - The element symbol consists of one or two letters of the element's name, which can be the English, Latin, or the name in another language.

Select all the statements that correctly describe a physical state.

- The physical state of a substance depends on the identity of the substance and the external conditons applied. - Solids, liquids, and agases are examples of physical states of matter.

What occurs when a molecular solid dissolves in water?

- The solid breaks into molecules that interact with water.

Which of the following are physical properties of ionic solids?

- They are solids at room temperature. - They are brittle solids.

In the solid form, the cesium and chloride ions that make up cesium chloride (CsCl) exist as ______.

- a Cs+ Cl- lattice

The symbol for the iodide ion has the following characteristics:

- a capital letter I - a charge of 1-

An ionic compound contains the following:

- a negatively charged anion - a positively charged cation - a balance of positive and negative charges

- NaBr - (NH4)2S - (NH4)3PO4 - ZnCO3

- contains a monoatomic anion and cation. - contains a polyatomic cation with a monoatomic anion - contains a polyatomic anion and polyatomic cation - contains a metal cation with a polyatomic anion.

(NH4)2S

- contains a polyatomic cation with a monoatomic anion

Which of the folliwng are general characteristics of molecular compounds?

- contains only nonmetals - create nonelectrolytic solutions

Which of the following are general characteristics of molecular compoumds?

- contains only nonmetals - create nonelectrolytic solutions

Which of the following are general characteristics of molecular compounds?

- create nonelectrolytic solutions - contain only nonmetals

A substance that releases ions in solution when dissolved in water is called a(n) _______. This solution _____ conduct electricity.

- electrolyte, will

Ionic solids have very distinct properties due to their ordered crystal lattice. They have very ______ melting points and the solids are very ______.

- high ; hard

- 2+ - 1+ - 1- - 2-

- magnesium - cesium - bromine - selenium

IO4- IO3- IO2- IO-

- periodate - iodate - iodite - hypoiodite

- SeO4 2- - SeO3 2- - SO4 2- - SO 3 2-

- selenate - selenite - sulfate - sulfite

- NaCl - CH3CH2OH

- strong electrolyte - nonelectrolyte

The ionic compound BaI2 is water soluble. When a small amount of solid BaI2 is placed in small and stirred carefully, what happens?

- the BaI2 releases Ba2+ and I- ions. - the solid BI2 no longer appears visible to the naked eye.

Which of the following are general characteristics of ionic compound?

- the compound contains anions and cations. - the compound contains metals and nonmetals. - the compound has an overall charge of zero.

Which of the following are general characteristics of ionic compounds?

- the compound contains metals and nonmetals - the compound contains anions and cations - the compound has an overall charge of zero

The compound KBr is an electrolyte. This compound_________.

- will dissolve in wter to produce K+ and Br- ions. - produces a solution that will complete a circuit and light a bulb.

What is the percent hydrogen in glucose, if a 8.27-g sample of glucose contains 0.555 g of hydrogen?

6.71%

A description of the composition of a substance, using element symbols and subscripts, is known as a ________.

Chemical Formula

True or false: all samples of a given pure substance have the same composition, regardless of their origin.

True - among the things that define pure substancs is that pure substances have definite or fixed compositions.

Which of the following options correctly define an element symbol?

- An element symbol is a shorthand version of an element's longer name.

A 4.24-g sample of a compound contains 3.22 g carbon. What is the eprcent carbon in the sample?

75.9% - The percent carbon is determined by dividing 3.22 g/4.24 g and multiplying by 100.

Nonelectrolyte solutions contain ________ compounds. These compounds _____ dissociate into ions when dissolved in water.

- molecular, will not

- IO4- - IO3- - IO2- - IO-

- periodate - iodate - iodite - hypoiodite

- PF4 - CuBr - FeCO3

- molecular compound - ionic compound with monoatomic ions - ionic compound with a polyatomicion

Select all of the relationships below that are correct for the compound Na2SO4+.

- 2 Na+ ions / 1 So4^2- ion. For every formula unit of sodium sulfate, there are 2 sodium ions and 1 sulfate ion. - 1 Na2So4 / 2 Na+ ions

Select all the statements that correctly describe a compound.

- A compound is described by a chemical formula that includes the symbols for the elements that make up the compound. - A compound is a substance composed of two or more elements combined in definite proportions. - A compound is a type of pure substance and has properties different from those of its component elements.

Which of the folliwng compounds contain polyatomic ions?

- Al(NO3)3, BaCO3, NH4

Select all the statements that correctly describe mass and/or weight.

- Weight can be measured on a scale or balance. - The interaction of mass with gravity creates weight.

Potassium chloride is used medically as an electrolyte replenisher. Determine the mass of potassium in a 250-mg tablet of potassium chloride. Potassium chloride is 52.4% potassium by mass.

131 mg - idfk how to get this lol

Which of the following ratios relfects the appropriate units for molar mass?

g / mole

MgBr2 is a(n) ________ solid. It will therefore be relatively _____ solid.

ionic, hard.

A _______ consists of two or more ______ and may vary in compositon.

mixture, pure substances

A(n) _______ is the smallest unit of an element that has the chemical properties of that element. Two or more of these units can be bound together in a discrete arrangement to form a(n) ___________.

- Atom, molecule.

Select all the options that represent general properties of metals.

- Metals conduct electricity. - Metals are shiny. - Metals conduct heat.

Select all the statements that correctly describe facts about elements.

- Some elements have been synthesized by scientists. - Some elements are isolated from natural sources on Earth. - Elements are building blocks of matter.

The ionic compound BaI2 is water soluble. When a small amount of solid BaI2 is placed in water and stirred carefully, what happens?

- The BaI2 releases Ba2+ and I- ions. - The solid BaI2 no longer appears visible to the naked eye. herf

Select all the statements that correctly describe the features of the periodic table.

- The elements in each column of the periodic table share similar properties. - Each column in the periodic table is called a group or family of elements.

A substance composed of two or more elements combined in definite proportions is called a ______.

Compound

Transition Elements

Groups 3-12

True or false: ionic compounds contain a combination of oppositely charged cations and anions in a specific ratio to produce a compound with a given whole-number charge.

False - ionic compounds do contain cations and anions in ratio of these components that gives an overall neutral (zero) charge.

True or false: Ionic compounds contain a combination of oppositely charged cations and anions in a specific ratio to produce a compound with a given whole-number charge.

False ; ionic compounds do contain cations and anions in a ratio of these components that gives an overall neutral (zero) charge.