Kush Finals

A gas with an unknown pressure has its container expanded. The original volume of the container is 15 L and the new volume is 45 L. If the new pressure of the gas is 42 pa., what was the original pressure of the gas? The temperature is kept constant.

126 Pa

Convert 16.3 g/mL to kh/L

16.3 kg/L

Convert 98 degrees Celsius to degrees Fahrenheit and to Kelvin

208.4 degrees Fahrenheit , 371 K

A gas with a pressure of 75 Pa is compressed. The new pressure is 200 Pa. If the original volume of the gas was 90kL, what is the volume of the gas after it is compressed? The temperature is kept constant.

33.75 kL

How much of Earth's crust is composed of Potassium and Sodium, according to the pie chart?

5.4%

A gas is heated from an unknown temperature to 560 K. If the original volume was 90 L, and the new volume is 95L, what was the original temperature of the gas? The pressure of the gas is kept constant.

530.53 K

A sample of matter has a density of 2.5 g/ml and a volume of 245 mL. What is its mass in grams.

612.5 g

Element J has exactly four isotopes: J-60, J-67, J-72, and J-73. J-60 has an abundance of 70% , J-67 with an abundance of 9%, and J-72 with an abundance of 18%. Calculate the atomic mass of J.

63.18

Convert 78 m to cm.

7800 cm

How many moles of oxygen gas, O2 is 287.982 grams of oxygen gas?

9 mol

Express 9623.3 in scientific notation

9.6233 x 10*3

What are the main points of Dalton's atomic theory?

All elements are composed of atoms. All atoms of the same elements have the same mass Atoms of different elements have different masses Compounds contain atoms of more than one element In a particular compound, atoms of different elements always combine in the same way.

Some liquid products are sold in aerosol cans. Gas is used to propel the liquid out of the can. Why should an aerosol can never be thrown into a fireplace or incinerator?

At a high temperature, the gas pressure might increase too much, causing the can to explode.

Which element has a higher melting point: potassium or calcium? Why?

Calcium because calcium is able to contribute twice as many electrons, compared to potassium, to the metallic bonds.

Which pair has the same electron configuration?

Cl- and Ar

Classify the following chemical reaction. 2C2H6 + 702 ---- 4C02 + 6H20

Combustion

Identify SIX common phase changes.

Condensation Deposition Freezing Sublimation Melting Vaporization

Select the three main branches of natural science

Earth Science Life Science Physical Science

What did Bohr contribute to modern atomic theory?

Electrons have energy levels with specific amounts of energy.

How do chemical reactions involve energy?

Energy is either released or absorbed

What are the main two types of mixtures?

Heterogenous and homogeneous

How does the scientific process start and end?

It begins with curiosity and ends with discovery.

Rice is typically needs to be cooked in boiling water. But, the rice will be burnt if there is no liquid water. An automatic rice cooker has built in temperature sensor in its pot. When should the rice cooker be shut off?

It should be shut off when the temperature is slightly higher than waters boiling point.

The ability of a solid to be hammered into a sheet without shattering is called

Malleability

Who is credited with arranging the elements in such a way that elements in similar properties would end up in the same column?

Mendeleev

Ammonia, NH3, can be made by reacting hydrogen gas and nitrogen gas. Which of the following chemical equations demonstrates this correctly? (Remember, the equation should be balanced, too)

N2 + 3H2 --- 2NH3

Based on electron dot diagrams, what is the formula for a covalently bonded compound of nitrogen and hydrogen?

NH3 (NH little three)

Identify the 3main subatomic particles.

Neutrons Electrons Protons

Identify the THREE MAIN categories that are used to classify elements in the periodic table

Nonmetal Metalloids Metals

Identify the three factors that affect gas pressure

Number of particles Temperature Volume

What is the chemical formula for sulfur dibromide?

SBr2

Which of these statements best describes a physical change in a pure substance?

Some of the properties of the substance change, bu the material remains the same.

What five factors influence reaction rate?

Stirring (agitation) Surface area Concentration Catalysts Temperature

What holds metal ions in a metal lattice?

Strong bonds between metal cations and the surrounding valance electrons.

What happens to the charge on atoms when they form a polar covalent bond?

The atom that has a greater attraction for electrons will get a partial negative charge

What happens to chemical bonds as a chemical reaction occurs?

The chemical bonds within the reactants break, and they reform within the products.

What subatomic particle did JJ Thompson discover during his cathode ray experiments?

The electron

What major change happens as you move from left to right across the periodic table?

The elements become less metallic and more nonmetallic in their properties.

Nitrogen has two electrons in its first energy level and five in its second. Compare the relative energies of these electrons.

The five electrons in the second energy level have more energy than the two electrons in the first.

Identify the TWO factors that affect the atomic mass of an element.

The masses of an elements isotopes Distribution of an elements isotopes

How do isotopes of an element differ?

The number of neutrons

How is it possible for Mendeleev to predict the properties of elements that had not been discovered?

The predictions were based on the properties of nearby elements and of those in the same column

What do the name and formula of a molecular compound describe?

The type and number of atoms in a molecule of the compound.

An atomic nucleus contains 30 protons and 38 neutrons. What time of an atom is this?

Zinc-68

When an atom loses an electron it forms a(n)

cation

You can be certain that a chemical change has occurred when

new substances form

An atomic mass unit is

one twelfth the mass of a carbon-12 atom

Identify all 5 known states of matter

plasma solid liquid gas Bose-Einstein condensates

At room temperature (defined as 20 degrees Celsius) as a substance with a melting point of 40 degrees Celsius is a

solid

If you spill bleach (sodium hypochlorite) on denim jeans, you typically see that the wet area is no longer blue. Is that change likely to be a chemical change?

yes