Answer: it’s the first one ☝️
Mass NEVER changes
Answer:
B. Q > K precipitate will form
Explanation:
The reaction is;
Ba(NO3)2(aq) + Na2CO3(aq) ------> BaCO3(s) + 2NaNO3(aq)
Hence the reaction could form a precipitate of BaCO3.
Number of moles of carbonate ions = 50/1000 * 0.10 M = 5 * 10^-3 moles
Number of moles of Barium ions = 20/1000 * 0.10 M = 2 * 10^-3 moles
Total volume after reaction = 20ml + 50ml = 70 ml or 0.07 L
Molarity Barium ions = 5 * 10^-3 moles/ 0.07 L = 0.07 M
Molarity carbonate ions = 2 * 10^-3 moles/ 0.07 L =0.03 M
Q = [Ba^2+] [CO3^2-] = 0.07 * 0.03 = 2.1 * 10^-3
But K = 2.58 × 10
^−
9
We can clearly see that Q>K therefore precipitate will form
Molar concentration is the amount of solute in moles divided by 1 liter of solvent. Then to answer this question, you need to convert the 23g of ammonium chloride into mole unit. Since the mass of nitrogen = 14, helium =1, and chlor= 35.453 then the molecular mass of (NH4)Cl should be: 14+4+35.453= 53.5
Then, the molarity should be: 23g/ (53.5gr/mole)/ (500ml/1000ml)= 0.86molality
This has only only three sig figs because it is 546.000 the zeros are just place holders so thus meaning they are not significant. It is just another way to write 546 because in that number there is also 3 sig figs. They are just trying to throw you off. Just watch out because if the example is 540 then it is just two significant digits, and it were to be 540. then it be three cause that "." makes the zero significant. <span />
Answer:
The false statement is d Avery,Macleod and McCarty showed that DNA is the genetic information of cells and RNA is the genetic information in the viruses .
Explanation:
Avery,Macleod and MacCarty showed that DNA is the genetic material of the cell.
On the other hand Fraenkel, Conrat and Sanger carried out their experiment on tobacco mosaic virus to prove that RNA act as genetic material in some viruses.
