Suppose the Cu ions are produced by the reaction of 0.94 g of copper turnings with excess nitric acid. How many moles of Cu are produced?

0.0148 moles

Explanation:

Solid copper is oxidized with HNO₃:

Cu + 4HNO₃ → Cu²⁺ + 2 NO₃⁻ + 2H₂O + 2NO₂

Where 1 mole of Cu produce 1 mole of Cu²⁺ when nitric acid is in excess.

Moles of Cu that react (Molar mass Cu = 63.546g/mol):

0.94g * (1mol / 63.546g) = 0.0148 moles of Cu

And moles of Cu²⁺ produced are also:

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

the answer is definitely c.