Chem 10 HN study guide -- Tobin

What should you do in a lab if you have to evacuate it?

close containers, turn off heat, shut off gas

Given a metal object with a mass of 200 grams and a volume of 50 cm³, calculate the density of the object

4 grams per cubic centimeter

What are the basic metric units and symbols for mass, volume, and density?

Mass: grams (g) Volume: liters (L) for liquids, cubic centimeters (cm³) for solids Density: grams per cubic centimeter (g/cm³)

What does the prefix 'milli-' mean, and what is its symbol?

it means one thousandth (0/001) and has a symbol of m

Convert 2500 milligrams to grams using dimensional analysis

2.5g

What is the definition of significant digits in a measurement

Measurements that are known with certainty with one final digit that is estimated

How many significant digits are in the measurement 0.004560

four sigfigs

Round 123.4567 to four significant digits

123.5

If you multiply 3.42 by 2.1, how many significant digits should the result have

7.2

Convert 0.000123 to scientific notation

1.23×10-4

2×103 multiplied by 3×104

6×107

Define accuracy and precision

accuracy is how close to the actual value something is and precision is how well grouped an instrument’s measurements are

Calculate the percent error if the experimental value is 45 g and the accepted value is 50 g

10%

Compare the precision of a graduated cylinder and a beaker when measuring 50 mL of water

a graduated cylinder is more precise since it has more markings or smaller increments

Classify the following as an element, compound, homogeneous mixture, or heterogeneous mixture: salt (NaCl), air, salad, and gold (Au)

Salt (NaCl): Compound, Air: Homogeneous mixture, Salad: Heterogeneous mixture, Gold (Au): Element

Identify whether the following are chemical or physical changes: burning wood, melting ice, rusting iron, dissolving sugar in water

Burning wood: Chemical change, Melting ice: Physical change, Rusting iron: Chemical change, Dissolving sugar in water: Physical change

Describe the properties of solids, liquids, and gases in terms of shape and volume

Solids have a definite shape and a definite volume. Liquids have a definite volume but take the shape of their container. Gases have neither a definite shape nor a definite volume; they expand to fill their container.

Explain where on a warming curve solids, liquids, gases, melting points, or boiling points would be

solid is at the initial segment, melting point is next, then it becomes a liquid, then it heats up to its boiling point, finally it turns into a gas

Describe the processes of sublimation and deposition

sublimation is when a solid changes directly to a gas and deposition is when a gas changes directly into a solid

Calculate the energy needed to heat 100 g of ice at 0°C to water at 100°C. Specific heat of water is 4.18 J/g°C, heat of fusion is 334 J/g, and heat of vaporization is 2260 J/g

75300 J

Democritus

proposed that matter is composed of small, indivisible particles called atoms

What are the main points of John Dalton's atomic theory, and what are its main flaws

Dalton argued that all matter is composed of indestructible atoms (flaw), all atoms are identical in mass (flawed), compounds are formed by combinations of different atoms, and that a chemical reaction is a rearrangement of atoms.

Rutherford

he observed that atoms have a small, dense, positively charged nucleus using the gold foil experiment

Thomson

he discovered electrons through his cathode ray experiments and proposed the plum pudding model

Bohr

He specified discoveries regarding electron orbits

Interpret the isotopic notation 3115P

This isotope has 15 protons, electrons, and 16 neutrons

Write the balanced nuclear equation for the alpha decay of Uranium-238

23892U → 23490Th + 42HE

Calculate the average atomic mass of an element with 75% isotope X−35 (mass = 35 amu) and 25% isotope X−37 (mass = 37 amu)

35.5 amu

Convert 4 moles of water to grams given the molar mass of water is 18 g/mol

72 g

Calculate the energy, wavelength, and frequency of a photon emitted when an electron in a hydrogen atom transitions from the n=3 to n=2 energy level. (Use appropriate constants)

energy is 4.971×10-19 J, wavelength is 6.562×10-7 m, frequency is 4.57×1014 Hz

If a p sublevel has three boxes and two of them are filled with paired electrons what rule does it violate?

Hund’s

Write the electron configuration for potassium

1s2, 2s2, 2p6, 3s2, 3p6, 4s1

What element is defined by [XE] 6s2

barium

Write the name and correct formula for the ionic compound formed between iron (II) ions and sulfate ions

Iron 2 Sulfate, FeSO4

Given that a compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen, determine its empirical formula

C2H5O4

Define the properties of metallic solids

they are Conductive, Malleable, Shiny, and have Strong bonds, as well as High melting and boiling points

What are the 7 diatomic elements

BrINClHOF

Rank the relative strength of triple bonds

Triple Bonds have the shortest bond length and highest bond strength among single, double, and triple bonds

Calculate the number of molecules in 5 grams of water

1.67×1023 molecules

Draw the 3D shape of the CH4​ molecule

Carbon has 4 single bonds, resulting in a tetrahedral shape. Draw the carbon atom in the center with four bonds extending outward, represented by wedges and dashes.

Identify the type of intermolecular forces present in the compound CH3Cl

it has dipole-dipole interaction due to electronegativity differences between carbon and chlorine

Write the skeleton equation for the reaction described by the word equation: "Sodium chloride reacts with silver nitrate to produce silver chloride and sodium nitrate."

NaCL (aq) + AgNO3 (aq) → AgCl (s) + NaNO3 (aq)

Classify the following reaction: "2H2(g) + O2(g) → 2H2O(l)"

it is a synthesis reaction

In the complete ionic equation for the reaction between lead(II) nitrate and potassium iodide, identify the spectator ions

the spectator ions are K+ and NO3-

Determine whether the following reaction is a redox reaction: "2Na + Cl2 → 2NaCl"

this is a redox reaction because Na oxidizes and chlorine reduces

Calculate the mass of calcium carbonate (CaCO3) required to produce 50.0 grams of calcium oxide (CaO) according to the reaction CaCO3→CaO+CO2

49.99 g

Convert a pH of 3.0 to [𝐻+]

1×10-3

Write the net ionic equation for the neutralization reaction between hydrochloric acid and sodium hydroxide

H++OH- → H2O

does a catalyst raise or lower the activation energy of the reaction?

it lowers the activation energy by providing a pathway with a lower activation energy barrier

What is the equilibrium constant expression (K) for a reversible reaction?

The equilibrium constant expression (K) is the ratio of the concentration of products to the concentration of reactants, each raised to the power of their respective stoichiometric coefficients.

A sample of gas occupies a volume of 2.50 liters at a temperature of 25°C and a pressure of 1.00 atm. If the pressure is increased to 1.50 atm while keeping the temperature constant, what will be the new volume of the gas?

1.67