Answer:
Absorbed, endothermic
Explanation:
Based on the heat of reaction, chemical reactions may be classified as endothermic or exothermic.
In an endothermic reaction, heat is absorbed from the surrounding. As heat is absorbed from the surrounding, the reaction vessel feels cool when touched.
On the other hand, in an exothermic reaction, heat is given out by the system to the surrounding and the reaction vessel feels hot when touched.
Hence the reaction is endothermic and energy is absorbed during the reaction.
I would say physical, because a physical change is affecting the form of a chemical substance, but not it's chemical makeup.
Fe(s) + CuSO4(aq) -> Cu(s) + FeSO4(aq) is the answer if you get it in advance...
Answer:
3.0 × 10²⁰ molecules
Explanation:
Given data:
Mass of ethanol = 2.3 × 10⁻²°³ g
Number of molecules = ?
Solution:
Number of moles of ethanol:
Number of moles = mass/ molar mass
Number of moles = 2.3 × 10⁻²°³ g / 46.07 g/mol
Number of moles = 0.05 × 10⁻²°³ mol
Number of molecules:
One mole = 6.022 × 10²³ molecules
0.05 × 10⁻²°³ mol × 6.022 × 10²³ molecules / 1 mol
0.30 × 10²⁰°⁷ molecules
3.0 × 10¹⁹°⁷ molecules which is almost equal to 3.0 × 10²⁰ molecules.
Answer:
copper is the only material composed of a single pure substance
Explanation:
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