Saturday, February 25, 2012

Alters Quiz #1 - Chapters 1, 2, 5, 9

Algae, paramecia and amoebae belong to what kingdom?
A. Plant
B. Fungi
C. Protista
D. Animal
A forest may contain populations of bacteria, fungi, deer, frogs and salamanders. These all combine to form a(n):
A. community
B. species
C. ecosystem
D. biosphere
In 1859 Charles Darwin published his book, On the Origin of Species, where he described the:
A. cell theory
B. theory of evolution
C. principles of heredity
D. gene theory
Simple microorganisms that live in hot springs and acid lakes belong to the:
A. Fungi
B. Bacteria
C. Protista
D. Archaea
The microscopist Rudolf Virchow believed that:
A. life arises from nonliving material
B. cells can arise only from preexisting cells
C. genes are the units of heredity
D. the cell is the unit of life


Which is not a key feature of the scientific method?
A. observation
B. statistic analysis
C. hypothesis formation
D. hypothesis testing
The hypothesis in a seed germination experiment is: Light is necessary for lettuce seed germination . Groups of lettuce seeds are placed in light with warm temperatures and adequate moisture. Another set of identical seeds is placed in the dark under the same conditions.What is the dependent variable?
A. warm temperatures
B. presence of darkness
C. presence of light
D. germination rate
In the Brand X fertilizer experiment, the fertilizer is the:
A. controlled variable
B. dependent variable
C. treatment
D. control
The hypothesis in a seed germination experiment is: Light is necessary for lettuce seed germination . Groups of lettuce seeds are placed in light with warm temperatures and adequate moisture. Another set of identical seeds is placed in the dark under the same conditions. In this experiment, what is the independent variable?
A. presence of light
B. germination rate
C. presence of darkness
D. warm temperatures
Which scientist published a book in the 1500s giving evidence the Earth orbits the sun?
A. Lyell
B. Darwin
C. Galileo
D. Copernicus

In order to visualize a specimen, an electron microscope uses _____ rather than light.
A. x-rays
B. a beam of protons
C. a thin layer of metal
D. a beam of electrons
The model of the cell membrane that is widely accepted today is the:
A. cytoskeleton model
B. endosymbionic theory
C. fluid mosaic model
D. cell theory

Pressure that builds up in plant cells and gives rigidity to them is called:
A. turgidity
B. equilibrium
C. a concentration gradient
D. plasmolysis
Transport proteins that facilitate the movement of water molecules across the cell membrane are:
A. enzymes
B. aquaporins
C. carrier proteins
D. receptor proteins
Prokaryotic cells arose on Earth more than:
A. 4.5 billion years ago
B. 1 million years ago
C. 3 billion years ago
D. 3 million years ago


The organism, Neurospora, is a(n):
A. plant
B. mold
C. protist
D. alga
Which do scientists hypothesize is a function of DNA repeats?
A. All of the above
B. protection of other DNA sequences
C. involved in gamete production
D. structural or organizational role in chromosomes
Extra sequences of nucleotides that intervene between the polypeptide-specifying portions of a gene are called:
A. exons
B. telomeres
C. promoters
D. introns
A complex of DNA and histone is called a(n):
A. nucleus
B. nucleolus
C. nuclein
D. nucleosome
The discovery that bacteria can transfer genetic material to other bacteria in transformation was made by:
A. Chargaff
B. Avery
C. Levene
D. Griffin

Tuesday, February 14, 2012

Reactions

What is the correct value for Avogadro's number?
A. 6.022 × 102.3
B. 6.022 × 1033
C. 6.023 × 1022
D. 6.022 × 1023
E. none of the above
What is the mass of 1.56 × 1021 atoms of magnesium in grams?
A. 4.72 × 10-5
B. 0.0630
C. 1.07 × 10-4
D. 0.142
E. none of the above
Calculate the molar mass of ammonium carbonate.
A. 88.05 g/mol
B. 96.09 g/mol
C. 78.05 g/mol
D. 112.09 g/mol
E. none of the above
What are the coefficients for the following reaction when it is properly balanced?___HCl + ___Mg → ___MgCl2 + ___ H2
A. 2, 1, 2, 2
B. 2, 1, 1, 1
C. 1, 2, 1/2, 1
D. 1, 1, 1, 2
E. none of the above
What type of reaction is the generic equation A + BC → AC + B?
A. synthesis/combination
B. double-displacement
C. decomposition
D. single displacement
E. none of the above
A precipitate is expected to be formed when an aqueous solution of sodium sulfate is added to an aqueous solution of
A. iron(III) chloride.
B. magnesium chloride.
C. barium chloride.
D. potassium chloride.
E. none of the above
How many moles of sodium metal are needed to make 3.6 moles of sodium chloride? Given the reaction: 2Na + Cl2 → 2NaCl
A. 3.6
B. 7.2
C. 1.8
D. 0.9
E. not enough information
What is the limiting reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3
A. Al
B. Al2O3
C. O2
D. both Al and O2
E. not enough information
The theoretical yield of a reaction is 75.0 grams of product and the actual yield is 42.0g. What is the percent yield?
A. 75.0
B. 178
C. 56.0
D. 31.5
E. none of the above
A chemist wishes to perform the following reaction: N2 + 3 H2 → 2 NH3 If only 14.0 g of N2 is available, what is the minimum amount, in grams, of H2needed to completely react with this quantity of N2?
A. 3.03 g
B. 1.01 g
C. 1.51 g
D. 6.06 g
E. none of the above

Monday, January 30, 2012

Atoms, Molecules, Compounds

Group 7A elements are also called:
A. halogens.
B. alkaline earth metals.
C. alkali metals.
D. noble gases.
E. none of the above
An atom containing 7 protons, 8 neutrons, and 7 electrons
A. is charge-neutral.
B. is an oxygen atom.
C. is an ion.
D. cannot exist.
E. none of the above
What is the charge on the ion formed by aluminum?
A. 13+
B. 3+
C. 3-
D. 5-
E. none of the above
The names of the elements whose symbols are Si, P, Mn, and S are respectively,
A. silicon, phosphorus, manganese, and sulfur.
B. silicon, potassium, magnesium, and sulfur.
C. silicon, phosphorus, magnesium, and sulfur.
D. silicon, potassium, magnesium, and sodium.
E. silver, phosphorus, magnesium, and sulfur.
How many neutrons are present in Ne-22?
A. 10
B. 22
C. 32
D. 12
E. none of the above
Which statement below accurately describes the contributions of Dalton?
A. created the modern periodic table
B. discovered the existence of electrons
C. ancient Greek philosopher who proposed that matter was continuous
D. proposed the modern Atomic Theory
E. none of the above
Which of the following is a molecular compound?
A. nitrogen monoxide
B. calcium acetate
C. barium sulfide
D. potassium hydroxide
E. none of the above
How many oxygen atoms are in the formula Al2(CO3)3?
A. 1
B. 9
C. 6
D. 3
E. none of the above
Choose the pair of names and formulas that do NOT match.
A. copper(II) nitride: Cu3N2
B. copper(II) nitrite: Cu(NO2)2
C. copper(I) nitrate: CuNO3
D. copper(II) nitrate: Cu(NO3)2
E. all of these are correct
What is the formula mass for potassium nitrate?
A. 85.11 amu
B. 92.99 amu
C. 117.11 amu
D. 101.10 amu
E. none of the above

Sunday, January 15, 2012

Calculations and Research

A sample of wood with a mass of 3.0 grams was burned in an open dish. The ashes weighed 1.2 grams. What happened to the rest of the wood?
A. The remaining 1.8 grams was converted into heat.
B. Nothing, the burned wood simply has a mass of 1.2 grams.
C. The remaining 1.8 grams was converted into gaseous compounds.
D. The remaining mass was destroyed.
E. none of the above

C
Who discovered the atomic theory?
A. Antoine Lavoisier
B. John Dalton
C. Nivaldo Tro
D. John Dalton and Antoine Lavoisier
E. none of the above

B
The correct scientific notation for the number 0.00050210 is:
A. 5.021 × 10^-4
B. 5.0210 × 10^-4
C. 5.0210 × 10^4
D. 5.021 × 10^4
E. none of the above

B
How many low dose 81 mg aspirin tablets can be made from 1.21 kg of aspirin?
A. 1.5 × 10^3 tablets
B. 1.21 × 10^3 tablets
C. 1.21 × 10^4 tablets
D. 1.5 × 10^5 tablets
E. 1.5 × 10^4 tablets

E
A lead ball has a mass of 55.0 grams and a density of 11.4 g/cm3. What is the volume of the ball?
A. 4.82 mL
B. 0.207 mL
C. 4.82 L
D. 0.207 L
E. none of the above

A
Determine the answer to the following equation with correct number of significant figures: (4.123 × 0.12) + 24.2 = ________
A. 24.70
B. 25
C. 24.695
D. 24.7
E. none of the above

D
Which state of matter has atomic spacing that is close together and indefinite shape?
A. gas
B. plasma
C. liquid
D. solid
E. none of the above

C
A pure substance is:
A. composed of two or more different types of atoms or molecules that has constant composition.
B. composed of only one type of atom or molecule.
C. composed of two or more different types of atoms or molecules combined in variable proportions.
D. composed of two or more regions with different compositions.
E. none of the above

B
How many joules are there in a 255 Calorie (nutritional calorie) snack bar?
A. 1.07 × 106
B. 1.07 × 103
C. 6.09 × 104
D. 2.55 × 105
E. none of the above

A
What is the value of 335 K on the Celsius temperature scale?
A. 167
B. 608
C. 66.4
D. 62
E. none of the above

D