HW Quiz Lessons 74-79

Which has more mass? 1.) Hydrogen mole or Carbon mole 2.) Aluminum mol or iron mol 3.) Copper mol or Gold mol 4.) 5 mols of Carbon or a mol of Gold

1.) Carbon mol 2.) Iron mol 3.) Gold mol 4.) Gold mol

List these compounds in order of increasing moles of molecules: 2.0 g CH4O, 2.0 g, H2O, 2.0 g C8H18.

1.) H2O 2.) CH4O 3.) C8H18

Which has more moles of metal atoms? A) 10g calcium or 10g calcium cloride B) 5g sodium cloride or 5g of sodium fluoride C) 2g iron oxide or 2 iron sulfide

10g Calcium 5g Sodium fluoride 2g iron oxide

There are 8.0 mol of H atoms in 2.0 mol of CH4O molecules. How many moles of H atoms are there in 2.0 mols of C2H6O molecules

12 Moles

What is the mass of 5 mol of iron oxide

159.6 g/mol

What is the mass of a mol of iron oxide

159.69 g/mole

Which has more moles of oxygen atoms, 153 of BaO, or 169 g of BaO2? Show your work.

169 g BaO2

Suppose that you have 740 tiny plastic beads and 740 marbles. Which sample has more mass? Explain your thinking.

740 marbles will have a greater mass that 740 tiny plastic beads because the mass of a single marble is greater that the mass of a single bead.

How many grams of carbon molecules are in 1 mol of each substance A) Methane C B) Methanol C C) Ethanol C2

A) 12 B) 12 C) 24

Which has more moles of molecules, 1 Methoanol, CH4O or 1 ethanol C2H6O

Methanol

Give the molar mass for the elements listed. Nitrogen Neon Chlorine Copper

Nitrogen = 14.0067 Neon = 20.1797 Chlorine = 35.453 Copper = 63.546

Explain how to determine the molar mass of sodium chloride, NaCl

First, find the AMU of the combined compound. Then convert the AMU into molar mass by the molar mass of NaCl can be calculated for finding the atomic mass of sodium (22.99 g/mol) and the atomic mass of chlorine (35.45 g/mol) and combining them. The molar mass of NaCl is 58.44 g/mol.

Which contains more atoms? 12 grams of H, or 12 grams of C 27 grams of Al, or 27g grams Fe 40 grams of Ca, or 40 grams of Na 40 grams of Ca, or 60 grams of Zn 10 grams Li, or 100 grams Pb

Hydrogen Aluminum Sodium Iron Lithlum

Explain how you can use mass to count large numbers of objects?

If you know the mass of an individual object in a large group of objects with the same mass, you can use it and the total mass of calculate the total number of objects.

What does the percent error tell you?

It expresses how accurate their measurements are. (Observed Value - Actual Value) ------------------------------------ x 100% Actual Value

What is meant by the term molar mass? What unit of measure is this given in?

It is the mass of one mole of atoms of an element. It is given in the average atomic mass. Molar mass is the mass of a given substance divided by the amount of that substance, measured in g/mol

Which of these has the most chromium A) 1.0 g Chromium chloride 2 B) 1.0 g Chromium chloride 3 C) 1.0 g Chromium oxide

B

List these compound in order of increasing mass in grams; 2.0 mol SiCl4, 2.0 mol PbO, 2.0 mol Fe2O3.

SiCl4, Fe2O3, and PbO

Describe the approximate size of 1 mol of a solid, a liquid, and a gas. In order least to greatest.

Solid-Liquid-Gas

How do you find the average atomic mass of atoms of an element? What unit of measure is this given in?

The average atomic mass of atoms of an element is given on the periodic table in units of AMU. To calculate the average atomic mass, multiply the fraction by the mass number for each isotope, then add them together.

How can you convert between moles of a substance and grams of a substance?

To convert between moles of a substance and grams of the substance, use the formula: Mass (g) = molar mass (x) moles

Explain how to determine the molar mass of sodium chloride (NaCl)

To determine the molar mass of sodium chloride, add the atomic mass of sodium and the atomic mass of chlorine to determine the mass of one unit of sodium chloride. The atomic mass in amu is the same as the molar mass in moles.

Why do chemists convert between moles and grams?

To specify the amount of a substance. A mole is simply a unit of measurement. Units are invented when existing units are inadequate. Chemical reactions often take place at levels where using grams wouldn't make sense

How is toxicity related to body weight?

To take size into account, the LD50 is reported in milligrams of substance perkilogram of body weight, mg/kg. That way the lethal does can be estimated for a mammal of any size.

How can scientists determain the toxicity of a substance?

Toxicities are measured by exposing laboratory animals of a substance in different dosages. Toxicity can be measured by the effect the substance has on an organism, a tissue or a cell.

Why might a 200 mg tablet of aspirin not have the same effect as a 200mg tablet of ibuprofen?

What atoms in both tablets differ