Determine the number of atom and the mass of Zr conium, silican and oxygen formular Zr SiO4 found in 0.3384 mol of zicon, Zr SiO4, a semi precious stone

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

What causes different colors to appear in the sky? the absorption of light by air molecules the reflection of light by bodies of water the greenhouse effect in earth's atmosphere the scattering and reflection of light by dust particles

Ascientist conducted an experiment and discovered that certain plants grow faster when given a particular amount of fertilizer. anouther scientist conducted the same experiment and got similar results. which concept does this best illustrate? a) repetition b) replication c) precision d) validity