Q: Determine the larger quantity between the following pair: $$5.3 \times 10^2$\ \mathrm{mL} or$$ $$6.4 \times 10^6$\ \mu\mathrm{L}.$$

$$6.4 \times 10^6$\ \mu\mathrm{L}$$

Q: In an experiment, you combine water $$(d = 1.00\ \mathrm{g/mL})$$ and hexane $$(d = 0.66\ \mathrm{g/mL}) in a $$beaker to make a mixture with a total volume of $$354.4\ \mathrm{mL}$$ and a total mass of $$312.9\ \mathrm{g}. $$Water and hexane do not mix. Calculate the volume of water and hexane in the mixture.

$$V_{\text{water}} = 215.8\ \mathrm{mL};\ V_{\text{hexane}} = 138.6\ \mathrm{mL}$$

Question 1

Suppose you wanted to create your own temperature scale based on propyl alcohol (propanol) since you were unsatisfied with both the Celsius and Fahrenheit units. The melting point and boiling point of propanol on the Celsius scale are $$-126\ ^\circ \mathrm{C}$$ and $$97.2\ ^\circ \mathrm{C}$$, respectively. In the new scale, you define the melting point and boiling point of propanol at $$0^\circ$$ and $$150^\circ$$, respectively. In terms of size, how does a propanol degree compare to a Fahrenheit degree?

Accepted Answer

$$0.723\ ^\circ \mathrm{P}/^\circ \mathrm{F}$$

Question 2

Determine the larger quantity between the following pair: $$5.3 	imes 10^2$\ \mathrm{mL} or$$ $$6.4 	imes 10^6$\ \mu\mathrm{L}.$$

Accepted Answer

$$6.4 	imes 10^6$\ \mu\mathrm{L}$$

Question 3

In an experiment, you combine water $$(d = 1.00\ \mathrm{g/mL})$$ and hexane $$(d = 0.66\ \mathrm{g/mL}) in a $$beaker to make a mixture with a total volume of $$354.4\ \mathrm{mL}$$ and a total mass of $$312.9\ \mathrm{g}. $$Water and hexane do not mix. Calculate the volume of water and hexane in the mixture.

Accepted Answer

$$V_{	ext{water}} = 215.8\ \mathrm{mL};\ V_{	ext{hexane}} = 138.6\ \mathrm{mL}$$

Question 4

Is a kilogram larger than a pound? By how much?

Accepted Answer

Yes, a kilogram is about 4.4 times larger than a pound

Question 5

An unknown element was observed to have the following properties:
1. It appears as a silvery liquid.
2. It has a density of $$13.53\ \mathrm{g/cm^3$} at $$room temperature.
3. It reacts with molecular iodine to produce a red solid.
4. It freezes at $$-38.83\ ^\circ \mathrm{C}$$ and boils at $$356.73\ ^\circ \mathrm{C}.
5. It $$forms a yellow solid when combined with dilute nitric acid.
Classify each property as physical or chemical.

Accepted Answer

Physical properties: 1, 2, 4; Chemical properties: 3, 5

Question 6

How many significant numbers for the volume of the metal bar in this illustration should be reported?

Accepted Answer

4

Question 7

Identify the correct statement about the atomic number and mass number of an atom.

Accepted Answer

Atomic number is equivalent to the number of protons while the mass number is equivalent to the sum of the number of protons and number of neutrons.

Question 8

Name the following elements with the symbols: Rh, Si, O, P.

Accepted Answer

Rhodium, Silicon, Oxygen, Phosphorus

Question 9

Identify which element does NOT exist as a diatomic gas at normal temperature and pressure.

Accepted Answer

Ne

Question 10

Identify which classification each element belongs to:
1) Mg
2) H
3) Cl
4) Ne
5) P
6) Fe

Accepted Answer

c) Mg: B, 2) H: I, 3) Cl: E, 4) Ne: F, 5) P: C, 1) 6) Fe: G

Question 11

Provide the correct formula for the following ions with correct charges:
I. Cyanide ion
II. Bisulfite ion
III. Perchlorate ion
IV. Oxalate ion
V. Phosphate ion
VI. Bromate ion

Accepted Answer

I. CN$$^-$$; II. HSO$$_3^-$$; III. ClO$$_4^-$$; IV. C$$_2O$_4$$^{2-}$$; V. PO$$_$$4^{3-}$$; VI. BrO$$_3^-$$

Question 12

What effect does excess oxygen have on the combustion reaction?

Accepted Answer

It ensures complete combustion, which is necessary for accurate analysis

Question 13

Calculate the empirical and molecular formula Butyric acid (molar mass = $$88.11\ \mathrm{g/mol}) $$that has a mass percent composition of $$54.53\% C$$, $$9.15\% H$$, and $$36.32\% O.$$

Accepted Answer

EF: C$$_2H$_4O$$; MF: C$$_4H_8$O_2$$

Question 14

How does a coffee filter exemplify the principle of filtration?

Accepted Answer

It separates coffee grounds (residue) from the liquid coffee (filtrate).

Question 15

Which of the following is a common error when applying the quadratic formula?

Accepted Answer

Mixing up the negative signs when calculating the $$b^2 - 4ac$ term under the square root.

Question 16

When a substance with the formula XBr$$_3$$ reacts with water, HBr and another acid, H$$_3XO$_3$$, are produced. H$$_3XO$_3$$ also contains three acidic hydrogens that react with KOH. After titrating a solution made up of $$3.67\ \mathrm{g} of $$XBr$$_3$$ and $$75.0\ \mathrm{mL} of $$water, it was discovered that $$87.3\ \mathrm{mL} of$$ $$0.132\ \mathrm{M}$$ KOH were needed to completely neutralize the acid. For the reaction of XBr$$_3$$ with water, write a balanced equation.

Accepted Answer

XBr$$_3 + 3 H$_2O$$ $$\rightarrow H$_3XO$_3 + 3 $$HBr

Question 17

You are provided the following reagents: antimony, platinum, nickel, aqueous copper(II) chloride solution, and hydrochloric acid solution. Assuming the reaction undergoes in an Erlenmeyer flask with a balloon attached to it, which combination of reagents would you use to obtain a chemical reaction that will fill up the balloon? Determine the identity of the gas that fills up the balloon.

Accepted Answer

nickel and aqueous hydrochloric acid; H$$_2(g)$$

Question 18

(a) What is the balanced net ionic equation for Sr(OH)$$_2 + $$CoCl$$_3$$ $$\rightarrow (b) $$What are the spectator ions?

Accepted Answer

(A) Co$$^{3+} (aq) + 3 OH$^- (aq$$) $$\rightarrow Co(OH$$)$$_3 (s) (B) Sr$^{2+}$$ and Cl$$^-$$

Question 19

At $$15.0^\circ \mathrm{C}$$, a gas occupies a volume of $$35.0\ \mathrm{L}$$ and has a pressure of $$1.36\ \mathrm{atm}. $$Calculate the volume (in L) it occupies at STP.

Accepted Answer

$$5.02 	imes 10^1$\ \mathrm{L}$$

Question 20

The term "alcohol" generally refers to the compound ethanol C$$_2H$_5OH (or $$ethyl alcohol). The heat of vaporization for ethanol is $$38.6\ \mathrm{kJ/mol}. If $$the combustion of ethanol is carried out in an adiabatic calorimeter, can its boiling point be measured? How much energy (in kJ units) is required to evaporate $$15.4\ \mathrm{g} of $$ethanol at its boiling point from the liquid state to the gaseous state? The density of liquid ethanol is $$0.790\ \mathrm{g/mL}.$$

Accepted Answer

Yes; 25.8 kJ

General Chemistry Study Guidance: Unit 1 Exam - Set 1

Guida di studio - Domande di pratica

Study guide - Flashcard