Gen Chem

What volume of copper sulfate (159g) should be used in the reaction to deliver 0.8g of CuSO4 into the reaction mixture? Given 0.50M used

0.8g x 1 mol / 159g x 1L / 0.50 mol = 0.01 L

which gas would occupy more volume at a constant temperature and pressure; 1.5 g N2 or 1.5g of O2? 1. N2 because there are more moles 2. O2 because its molecules are larger 3. both occupy same volume 4. neither

1. N2 because there are more moles N has smaller molar mass so occupies more as a gas

How many moles of O2 are consumed if a 1.8kg of MnO2 (86.9g) are used in the reaction below? 2MnO2 + 4KOH + O2 --> 2K2MnO4 + 2H2O

1.8kg x (1,000g / 1kg) x ( 1 mol / 86.9g) x (1 mol H2 / 2 mol 2MnO2) = 10.4 mol

What volume of H2 gas will be generated in the reaction below if 10L of a 5M solution of K2MnO4 reacts at STP? 2K2MnO4 + 2H2O --> 2KMnO4 + 2KOH + H2

10L x (5M / 1L) x (1 mol H2 / 2 mol K2MnO4) x (22.4 L / 1 mol) = 560 L

If the solubility of a compound is 120g per 100 mL of water. What is the approx molar concentration of NaC9H7O4 solution used in the reaction?

120g / 100mL x 1,000mL / 1L x 1 mol / 202g NaC9H7O4 = 5.9 mol / L

What is correct e- configuration for Zn 2+ ?

1s2 2s2 2p6 3s2 3p6 4s0 3d10 electrons are removed from the sub shell with the highest n value first, so 4s would be highest

The mean serum urate concentration in a sample of urine was measured to be 64 mg/L. If a 2.0 mL solution sample is analyzed, what is the total mass of the serum urate present in the sample in g?

2.0 mLx (1 L / 1,000mL) x (64mg / 1L) x (1g / 1,000mg) = 1.3 e -4 g

What is max number of electrons allowed in a single atomic energy level in terms of the principle quantum number n?

2n^2

What is equation for the max number of electrons that can fill a sub shell?

4l + 2

Which bond is the longest and weakest? - O-H - C-C - C-H - C=O

C-C - bond disassociation energy is the energy needed to break bond. The larger the radius of an atom the longer and weaker the bond is. Also, bonds with less jumping of valence e- on periodic table are weaker, hence c-c

when dissolved in water, which of following ions is most likely to form a complex ion with H2O Na+, Fe 2+, Cl- , S 2-

Fe 2+

Why is F-H a weak acid?

Flourine has a small radius which makes the F-H a strong bond

Halogens

Group 17, make good leaving groups, the larger they are the better leaving group they become

what type of reaction occurs when sucrose is cleaved?

Hydrolysis of glycosidic bonds

In which compound does manganese have an oxidation number of +6? - MnO - MnO2 - K2MnO4 - KMnO4

K2MnO4 - group 1 elements O# = + 1 - group 2 elements O# = +2 - group 17 elements O# = -1 - group 16 elements O# = -2 K has a O# of +1 O has an O# of -2 so Mn will equal +6 if K2MnO4

What is the base dissociation constant of HCN?

Kb = (OH-) (HCN) / (CN-)

if delta G is neg then Keq is ...

Keq > 1

ketoses such as sucrose are expected to have a positive result on a Tollen test because: - Ketoses tautomerize into aldoses - ketoses are non reducing - ketoses are non hemiacetals

Ketoses tautomerize into aldoses Tollen test is used to identify the presence of aldehydes and hydroxy ketones

If the solubility constant is Ksp = 34.9 NaC9H7O4, what is the approximate concentration of acetylsalicynate (C9H7O4) in the saturated NaC9H7O4 solution used?

Ksp = [X]^x * [Y]^y 34.9 = X^2 x = 5.9

Pyranose vs. Furanose

Pyranose is a 6-membered ring. Furanose is a 5-membered ring.

ionization energy

The amount of energy required to remove an electron from an atom

which of following observations would provide the reaction product is pure: - one absorbance peak from size exclusion chromatography - two peaks on HPLC - two unique CH3- peaks - a single spot on a thin layered chromatography plate

a single spot on a thin layered chromatography plate -thin layered chromatography is used to determine purity of a compound based on polarity

alpha emission

atomic mass decreases by 4

beta decay/electron capture

atomic number decreases by 1

beta minus decay

atomic number increases by 1

increasing temperature does what to density?

decreases density so object inside will float D = mass / volume

electron falls from n = 4 to n = 1 is it absorbed or emitted

emitted, electron must lose energy to fall to ground state

which of following elemental groups is NOT included in representative elements? group 1 group 3 group 13 group 18

group 3

Which of following atoms only has paired e- in its ground state sodium, iron, cobalt, helium

helium also, noble gases only have paired electrons

speed of light travel:

index of refraction is inversely proportional to speed of light. A high index = slow light velocity

Antimony (Sb) is used in some anti parasitic medication specifically those targeting Leishmania Donovani What type of element is it? Metal Metalloid Halogen Nonmetal

metalloid

Which is the highest-energy orbital of elements with valence electrons in the n = 3 shell?

n - 1 3 - 1 = 2 d orbital s = 0 p = 1 d = 2 f = 3

Which of the following quantum number sets is possible n = 2, l = 1, ml = -1, ms = 1/2 n = 2, l = 2, ml = -1, ms = 1/2 n = 2, l = 2, ml = 1, ms = 1/2

n = 2, l = 1, ml = -1, ms = 1/2 remember l = n - 1

What determines the length of an elements atomic radius

number of valence e- and number of e- shells

if electrons have same ms (magnetic spin) then they are...

parallel

An infrared spectrum gives all of the following except: - spin-spin splitting of all atoms - signals that correspond to signaling and stretching - amount of light absorbed - amount of energy to stretch a bond

spin-spin splitting of all atoms

disproportion reaction

the same element in one oxidation state is simultaneously oxidized and reduced

the area enclosed by the PV loop is:

the work done