SGM Whiteboard Review Fall 2018

Draw a bohr model of Ca

How many protons, neutrons, and electrons are in titanium?

P: 22 N: 26 E:22

What are isotopes? How do you use isotopes in average atomic mass?

The average atomic mass of an element is the sum of the masses of its isotopes, each multiplied by its natural abundance

Write the electron configuration for phosphorus.

1s2 2s2 2p6 3s2 3p3

Why does oxygen have a -2 charge? Hint: electron configuration

1s2 2s2 2p4 To have a full octet, oxygen needs to gain 2 electrons 1s2 2s2 2p4 To have a full octet, oxygen needs to gain 2 electrons. This makes it have 2 more electrons than protons; making it a -2 charge

Explain the steps of the flame test. (where does the light come from)

Light comes from the electron moving from an excited state to a lower state; the energy released is in the form of light.

What happens to the atomic radius as you go from Cl to Na What happens to the atomic radius as you go from Cl to Na? Going down a group?

Name H2SO3

Sulfurous acid

Name HF

Hydrofluoric acid

Name Cu(CN)3

Copper (III) cyanide

Name N5H9

Pentanitrogen nonahydride

Name Cr2(SO4)3

Chromium (III) sulfate

Name SO3

Sulfur trioxide

Rank the following bonds from least to most polar. SiO Cl2 HF Element Electronegativity Cl 2.8 H 2.1 F 4.0 Si 2.0 O 1.8 Rank the following bonds from least to most polar. SiO Cl2 HF

SiO: 2.0-1.8= 0.2 Cl2: 1.8-1.8=0 HF:4.0-1.0=3.0 Cl2, SiO, HF

Which has a higher boiling point? CH4 or LiCl

LiCl because it is ionic Ionic bonds have higher boiling/melting points than covalent bonds

Rank the IMF’s in decreasing boiling/melting point

HB>D-D>LD

Write the balanced chemical equation: lithium reacts with copper(I)sulfide

2Li + Cu2S  Li2S + 2Cu

What are the products of potassium bromide reacting with iodide?

KBr + I2  No reaction

What are the products of AgNO3 and MgCl2?

2AgNO3 and MgCl2  2AgCl + Mg(NO3)2

What are examples of a chemical reaction?

Bubbles forms precipitate forms burning change in temperature color change (how?)

Which has a greater mass: 3.0 moles of CO2 or 3.0 moles of O2?

3.0 moles of CO2 x (44g/mole) = 132 g 3.0 of O2 x (32g/mole) = 96 g

What is the percent composition of hydrogen in water?

H2O % H = 2.0/(2.0+16) x 100 = 11.1%

What are the steps (poem) to calculate the empirical formula?

Percent to mass Mass to moles Divide by small multiply till whole

Once you have the Empirical formula, how do you calculate the molecular formula?

You will be given molecular mass (g/mole) 1. Find the mass of your E.F. 2. Divide the molecular mass by the E.F. mass 3. Multiply the whole number (from #2) by the subscripts of the E.F.

If 3.0 moles of HCl reacts with NaOH, how many grams of water will be produced?

HCl + NaOH  NaCl + H2O B 3. e. x. 0 C. -x. -x. +x. +x A. 0 x= 3. 0 3 HCl + NaOH  NaCl + H2O B 3.0 e.x. 0 0 C -x -x +x +x A 0 x= 3.0 3.0 moles of water is produced x (18g/mole) 54 g of water is produced

What are the steps to calculate the mass of an unknown metal What are the steps to calculate the mass of an unknown metal? Think calorimetry

1. Calculate the Q of water 2. Q of water = - Q of metal 3 1. Calculate the Q of water 2. Q of water = - Q of metal 3. solve for c of metal

Describe the energy transfer at point A; point B

At point A (solid), kinetic energy is increasing, potential is not changing At point B, the kinetic energy is not changing, but the potential energy is increasing to change from solid to liquid

Why does the volume change?

The temperature is increasing, making the particles move faster, which are hitting the sides of the container quicker, making the container get bigger

What are the solubility factors? List them

Smaller particles (increase particle size) Stirring Increase temperature

If you want to make 300 mL of a 0 If you want to make 300 mL of a 0.1 M HCl solution, how much of the 10 M should you use? How much water should you use?

10(x) = (0.1)(300) 3mL of 10M stock solution Amount of water: need to make 300 mL; use 3mL of 10M; water = 300 mL – 3 mL = 297 mL of water

How does adding salt to water, affect the boiling point?

Adding salt to water will interfere with the intermolecular forces between the water molecules, causing the boiling point to increase. The more solute, the higher the boiling point/lower the freezing point

How does dissociation of a base affect its concentration?

The higher the dissociation, the higher the concentration of the H+ The higher the dissociation, the higher the concentration of the H+. The higher the concentration, the lower the pH

What are the products of the neutralization reaction between NaOH and H3PO3?

Salt and water NaOH and H3PO3  Na3PO3 + H20