Answer:
Mass% Cr = 85.5%
Explanation:
<u>Given:</u>
Mass of CrBr3 sample = 0.8409 g
Mass of the AgBr precipitate = 1.0638 g
<u>To determine:</u>
The mass percent of Cr in the sample
<u>Calculation:</u>
The reaction of CrBr3 with silver nitrate results in the precipitation of the bromide ion as silver chloride (AgBr) and Cr as soluble Cr(NO3)2
CrBr3(aq) + 3AgNO3(aq)→ 3AgBr(s) + Cr(NO3)3(aq)
Molecular weight of AgBr =187.77 g/mol
Moles of AgBr precipitated is:

Since 1 mole of AgBr contains 1 mole of Cl, therefore:
# moles of Cl = 0.004478 moles
At wt of Cl = 35.45 g/mol


Mass%(Cr) = 100 - 14.50=85.5%
Answer:
See explanation
Explanation:
Copper II oxide is a base but not an alkali. An alkali is a soluble base. Since Copper II oxide is not soluble in water then it is not an alkali.
Let us recall that the change of colour of litmus with an alkali requires the presence of water. In the absence of water, solid Copper II oxide does not turn red litmus paper blue.
The ability to turn red litmus paper blue is commonly observed with alkalis and Copper II oxide is not an alkali.
Also recall that since Copper II oxide is not soluble, hydroxide ions are absent hence Copper II oxide does not turn red litmus paper blue.
They look like gases plasmas have no fixed shapes or volume and are less dense tan solids or liquids
I believe the answer is carbon dioxide
Answer:
open system
Coffee held in a cup is an open system because it can exchange matter water vapors and energy heat with the surroundings.