Module 1: Essential Ideas
A homogeneous mixture is also called a ____________.
solution
Which subatomic particle is found in the nucleus and has no charge?
Neutron
Determine the formula weight of BaSO₄. Provide an answer to two decimal places.
233.40 amu
The oxidation number of oxygen in O²⁻ is
-2
How many kcal are in 37.1 kJ?
8.87 kcal
A silver bar is an example of a(n)
A. Element B. Compound C. Mixture
A. Element
The element symbol for ytterbium is __.
Yb
Calculate the mass, in grams, of 269.0 atoms of cadmium, Cd (1 mol of Cd has a mass of 112.41 g).
5.03 × 10⁻²⁰ g
The precipitate formed when Fe(NO₃)₃ is mixed with KOH is
Fe(OH)₃
When molecules absorb heat, there is an increase in
the kinetic energy of the molecules.
Convert 618 mg to g
0.618 g
What is the atomic number for an element whose mass number is 145, which contains 84 neutrons per atom?
61
The density of helium in a balloon is 1.18 g/L. If a balloon holds 2.99 L of He, how many atoms of He are in the balloon?
5.32 × 10²³ atoms
What is the coefficient in front of the O₂ when the equation below is balanced (using only whole numbers and the lowest whole number ratio)? C₂H₆O(g) + O₂ (g) → CO₂(g) + H₂O (g)
3
The enthalpy for boiling water is 40.7 kJ/mol. What is the quantity of heat (in kJ) required to boil 356.1 g of water?
804 kJ
A liquid in the lab has a density of 1.17 g/cm³. What is the volume in liters of 3.02kg of the liquid?
2.58L
Determine the number of protons (p) and electrons (e) in Mg²⁺.
12 p, 10 e
What is the mass percentage of C in hydrochlorothiazide, C₇H₈ClN₃O₄S₂? Provide an answer to two decimal places.
28.24 %
What mass of tin (in g) would be required to completely react with 1.70 L of 0.350 M HCl in the following chemical reaction? Sn(s) + 4 HCl(aq) → SnCl₄ (aq) + 2 H₂(g)
17.7 g
The ∆Hvap for ethanol is 38.6 kJ/mol at its boiling point of 78.2 °C. Calculate ∆E for the vaporization of one mole of ethanol at this temperature.
35.7 kJ
The mass of a piece of metal is 28.3055 grams. When the piece of metal was dropped into a graduated cylinder that had an initial water volume of 7.34 cm³, the total volume was 9.84 cm³. What is the density of the piece of metal in g/cm³?
11.32 g/cm³
barium chromate
What mass of MgCl₂ in grams are in 215 mL of a 0.350 M solution of MgCl₂?
7.2 g
A 1.000 g sample of an unknown compound containing only carbon, hydrogen, and oxygen was analyzed through combustion analysis and yielded 2.579 g of CO₂ and 0.6536 g of H₂O. What is the compound's empirical formula?
C₂₁H₂₆O₅
In the following reaction, what is the quantity of heat (in kJ) released when 1.33 moles of CH₄ are burned? CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g) ∆H° = -802 kJ/mol
1.07 × 10³ kJ