What are the possible answers?
Answer:
D. her results are neither precise, nor accurate
Explanation:
Reason being that: First, she obtained four different result for an experiment ( obviously it's supposed to be one value for the different procedure or atleast very close range) sugar solution and all four values were far apart.
Answer:
A single compound reacts with itself.
Explanation:
Disproportionation is a chemical reaction,most times a redox reaction, in which a molecule is transformed into two or more dissimilar products. In a disproportionation reaction, the species are simultaneously oxidized and reduced to form at least two different products.
A typical example of a specie that disproportionate is the copper I ion as shown below;
2Cu^+(aq) ------> Cu(s) + Cu^2+(aq)
The two oxidation states of copper formed in the disproportionation are Cu(0) and copper (II).
Answer:
a) CaF₂.
b) 7.81g of CaF₂ are present.
Explanation:
a) The calcium ion has as charge Ca²⁺ and fluoride ion is F⁻, that means formula unit is:
CaF₂
b) 1 molecule of CaF₂ contains 2 anions, F⁻. Thus, the moles of CaF₂ is:
1.2x10²³ anions * (1 moleculeCaF₂ / 2 anions) = 6x10²² molecules of CaF₂
6.022x10²³ molecules = 1mol:
6x10²² molecules of CaF₂ * (1mol / 6.022x10²³molecules) = 0.10 moles CaF₂.
1 mole of CaF₂ has a mass of 78.07g:
0.10 moles CaF₂ * (78.07g / mol) =
7.81g of CaF₂ are present
