Answer:
3. turns pink and is basic
Explanation:
Phenolphthalein is a pH indicator that remains colorless in acidic solutions, but in basic solutions it turns pink at a pH equal to 10.
Phenolphthalein is a weak acid that loses H+ cations in solution. The phenolphthalein molecule is colorless, while the phenolphthalein-derived anion is pink. When a base is added, phenolphthalein loses H+, forming the anion and causing it to turn pink. The color change cannot be explained only on the basis of deprotonation, a structural change occurs with the appearance of a ketoenolic tautomerism.
Answer:
2C3H8O + 9O2 ==> 6CO2 + 8H2O ... balanced equation
moles propanol = 5.26 g x 1 mol/60.1 g = 0.0875 moles
moles O2 = 31.8 g x 1 mol/31.9 g = 0.997 moles O2
Propanol is limiting based on the mol ratio in balance equation of 2 : 9
To find mass of O2 (excess reagent) left over, we will first find moles O2 used up.
moles O2 used = 0.0875 mol propanol x 9 mol O2/2 mol propanol = 0.394 moles O2 used
moles O2 left over = 0.997 mol - 0.394 mol = 0.603 mol O2 left
mass O2 left = 0.603 mol O2 x 32 g/mol = 19.3 g O2 left over
John Dalton was the first scientist
Na 2Co3
1*23=23. 2*12=24. 6*16=96
23+24+96=143
(23*100)/143. (24*100)/143. (96*100)/143
=16%. =16.7%. =67.1%
