Chemistry, 03.11.2020 05:00, ElizabethF
Use the periodic table to identify the number of core electrons and the number of valence electrons in each case below.
Potassium (K): 1s22s22p63s23p64s1
18
core electrons
1
valence electrons
Iron (Fe): [Ar]4s23d6
18
core electrons
8
valence electrons
Argon (Ar): [Ne]3s23p6
10
core electrons
8
valence electrons
Magnesium (Mg): 1s22s22p63s2
10
core electrons
2
valence electrons
Answers: 2
Chemistry, 22.06.2019 08:00, katelyn0579
Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely. analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?
Answers: 1
Chemistry, 22.06.2019 17:30, katherineweightman
What will most likely happen in the absence of a cell membrane? a) photosynthesis will not take place. b) the cell will not store food, water, nutrients, and waste. c) energy will not be released during cellular respiration. d) substances will pass in and out of the cell in an uncontrolled manner.
Answers: 1
Use the periodic table to identify the number of core electrons and the number of valence electrons...
Mathematics, 26.11.2019 06:31
Spanish, 26.11.2019 06:31
Mathematics, 26.11.2019 06:31
Mathematics, 26.11.2019 06:31