Chemistry
Chemistry, 07.07.2020 20:01, tristanart5749

2 IU
When a chemical reaction occurs,
a phase change takes place
the physical and chemical properties of the products are different from the reactants
the physical and chemical properties of the reactants are the same as the properties of the products
the compounds can be separated by physical means

answer
Answers: 2

Other questions on the subject: Chemistry

image
Chemistry, 21.06.2019 22:30, mimireds5419
1. combine iron and copper (ii) sulfate solution. (hint: iron will form the iron (iii) ion) fe + cuso4 → 2. combine lead (ii) nitrate and potassium iodide solutions. pb(no3)2+ kl → 3. combine magnesium metal and hydrochloric acid solution. mg + hcl → 4. electrolysis (splitting) of water. h2o → 5. burning magnesium. mg + o2 →
Answers: 3
image
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
image
Chemistry, 22.06.2019 11:00, Adot23x
What is the molar mass of a gas that has density of 2.054 g/l
Answers: 2
image
Chemistry, 22.06.2019 17:00, olsen6932
Complete each row of the table below by filling in the missing prefix or missing exponent.
Answers: 1
Do you know the correct answer?
2 IU
When a chemical reaction occurs,
a phase change takes place
the physical and...

Questions in other subjects: