♥QT♥

in general, we assume that in a mixture, each component will show the same rf value it shows when it is run alone. sometimes the presence of a large amount of a second component will affect the rf value of a component of interest. suggest why this behavior is found?

2.) how could you use TLC as an aid in finding out how to seperate a large quantity of material (5 g) by column chromatography?

In the first part of this lab, you prepared a NaBr solution that is approximately 0.2 M. Considering that molarity is defined as moles of NaBr per liter of solution, give possible errors that are present in the procedures that will cause your actual molarity to be different from that calculated.

The mixing of aqueous solutions of chromium(III) nitrate and sodium sulfide produces brownish black powder as a precipitate.

1) write a balanced equation that describes the dissociation of chromium nitrate in water

2) write the balanced net ionic equation that describes the reaction

3) what are the spectator ions?

For the following reaction, MgBr2 (aq) + CuSO4 (aq)

1) write the balanced molecular equation. (Include phase labels)

2) what is the color of the precipitate

3) what is the final color of the solution

1.)What anion would ou add to only precipitate Fe^3+?

2.) what anion would you add only to precipitate Ba^2+?

1. which of the following might result in a human zygote with 45 chromosomes?

A) fertilization of a 23 chromosome human egg by a 22 chromosome sperm of a closely related species

B) an error in the alignment of chromosomes on the metaphase plate

C) failure of the egg nucleus to be fertilized by the sperm

D) lack of chiasmata in prophase I

E) an error in either egg or sperm meiotic anaphase

2. women (and all female mammals) have one active X chromosome per cell instead of two. what causes this?

A) the removal of methyl (CH3) groups from the X chromosome that will remain active

B) modification of the XIST gene so that it is active only on one X chromosome, which then becomes inactive

C) crossover between the XIST gene on one X chromosome and a related gene on an autosome

D) inactivation of the XIST gene on the X chromosome derived from the male parent

E) activation of the Barr gene on one of the two X chromosomes that then inactivates

3. What is a syndrome?

A) a group of traits typically found in conjunction with a particular chromosomal aberration or gene mutation

B) a characteristic that only appears in conjunction with one specific aneuploidy

C) a characteristic facial appearance

D) a group of traits, all of which must be present if an aneuploidy is to be diagnosed

E) a characteristic trait usually given the discoverer's name

you have a series of cells, all of which were derived from tumors, and you first need to find out which ones are malignant. what could you do?

A.) see which ones are not overproliferating

B.) measure metasis

C.) Time their cell cycles

D.) find out which ones have a higher rate of apoptosis

E.) Karyotype samples to look for unusual size and number of chromosomes

The atomic orbitals of two chlorine atoms combine to form the Cl2 molecule. Use the periodic table to determine the orbitals that overlap to form the Cl2 molecule (e.g., for the hydrogen atom the 1s orbitals overlap) and the noble gas that has the electron configuration analogous to the electron configuration of each bonded chlorine atom.

For example, to enter the atomic orbitals of two fluorine atoms that combine to form an F2 molecule and the corresponding noble gas, you would enter 2p,Ne.

Enter the symbol for the orbitals that overlap (e.g., for H2 enter 1s) and the chemical symbol of the noble gas separated by a comma.

N-3

A.) 5.53 x 10^23 atoms of Mg

B.) 1.801 x 10^23 atoms of Br

C.) 4.412 x 10^22 atoms of P

D.) 5.108 x 10^24 atoms of S

Determine the number os atoms in each of the following:

E.) 22.8 grams of Co

F.) 35.4 grams of Ag

G.) 12.3 grams of H

A.) 5.94 X 10^23 atoms of Cl

B.) 8.099 X 10^23 atoms of I

C.) 1.001 X 10^21 atoms of Au

1.) A mixture of Sand and salt is found to be 48% NaCl by mass. How many moles of NaCl are in 74 g of this mixture?

2.) A water solution of sulfuric acid has a density of 167 g.mL and is 75% H2SO4 by mass. How many moles of H2SO4 are contained in 400 mL of this solution?

1.) An organic compound is analyzed and found to be carbon 51.90%, hydrogen 9.80%, and chlorine 38.30%. what is the empirical formula of this compound?

2.) A sample of oxygen gas, O2, weighs 28.4 grams. How many molecuiles of O2 and how many atoms of O are present in this sample?

A.) 5.53 x 10^23 atoms of Mg

B.) 1.801 x 10^23 atoms of Br

C.) 4.412 x 10^22 atoms of P

D.) 5.108 x 10^24 atoms of S

Determine the number os atoms in each of the following:

E.) 22.8 grams of Co

F.) 35.4 grams of Ag

G.) 12.3 grams of H

__Al+__H2SO4 --> __H2 + __Al2 (SO4)3

How many grams of K2CO3 would you need to put on the spill to neutralize the acid according to the following equation?

2HBr(aq)+K2CO3(aq) ---> 2KBr(aq) + CO1(g) + H2O(l)

How many grams of carbon are needed to react with 510 of hematite?

a mixture was found to contain 3.10 g of sio2 0.38 g of cellulose and 6.72 g of calcium carbonate. What is the percentage of CaCO3 in this mixture?