Answer:
C
Explanation:
If the enthalpy change (i.e. Δ<em>H</em>) of a reaction is negative, then the reaction releases heat and is hence exothermic.
Hence, our answer is C.
Conversely, if Δ<em>H</em> is positive, the reaction absorbs heat and is endothermic.
Δ<em>H</em> tells us nothing about the speed of the reaction.
While Δ<em>H</em> influences free-energy change (Δ<em>G</em> = Δ<em>H</em> - <em>T</em>Δ<em>S</em>), we cannot predict the sign of Δ<em>G</em> given only Δ<em>H </em>(recall that a reaction is spontaneous if Δ<em>G</em> < 0).
Answer:
True.
Explanation:
hydrogen and oxygen=water or hydrogen oxide
H+O2=H2O.
Answer:
53 cm³
Explanation:
When the student used dilute sulfuric acid, the reaction was complete after 60 s, because no more hydrogen was formed in the next 10 s.
The reaction would go faster if the student used a more concentrated acid, but 53 cm³ of hydrogen is the most that would form.
Answer:
195.199grams
Explanation:
Fluorine has a molar mass of 18.99984 while calcium has a molar mass of calcium is 40.08.
1 mole of calcium fluoride has a mass of 40.08+2×18.99984
=78.0797 grams
if one mole has a mass of 78.0797 grams, then 2.5 moles have:
2.5 moles× 78.0797 grams/mole= 195.1992 grams
False, Molecules are made of atoms and atoms are made of quarks.
