B. she can ask people about their backgrounds
This requires listening, the rest do not
1) Silicon dioxide formula: SiO2 ....... 2 is a subscript for the O atom
2) From the formula you have 1 molecula of SiO2 contains 1 atom of SiO2
3) Then, 0.100 mol of SiO2 contains 0.1 mol of Si
4) Multiply by Avogadro's number: 0.100mol * 6.022*10^23 atoms/mol= 6.02*10^22 atoms
Answer: 6.02*10^22 atoms
Answer:
eight oxygen atoms
Explanation:
This formula shows that in one mole of this compound, there are 3 moles of Ca atoms that combine with 2 moles of the PO4(phosphate) groups, which gives a total of 2 moles of P atoms and 8 moles of 0 atoms.
Distillation is a technique used to separate pure liquids from a mixture of liquids by boiling the mixture to the respective boiling points of the components and selective condensation. The pure liquid separated out after the condensation of vapors is called distillate. The distillate collected is expected to be pure. The purity of the distillate can be measured by recording the boiling point of that liquid. For example, if we have water separated out it should boil at 100
otherwise it can be treated as impure.
As i am reading the problem, i notice they give two concentrations (M), a volume and asking for the other volume; this should be a hint that we need to use the dilution formula---> M1V1 = M2V2
M1= 2.55 M
V1= ?
M2= 0.75 M
V2= 125 mL
now, we plug in the values into the formula
(2.55 x V1) = (0.75 x 125)
V1= 36.8 mL
