B
a and c are unrelated
d: ph will increase
The answer is elements gain electrons. Oxidation reduction is elements lose electrons. And oxygen is added/lost can be a type of oxidation/reduction reaction.
To determine the amount of a substance in units of moles from units of grams, we need to determine the molar mass of the substance. <span>The </span>molar mass<span> is the </span>mass<span> of a given chemical element or chemical compound (g) divided by the amount of substance (mol). For CuF2, the molar mass </span><span>101.543 g/mol. We calculate as follows:
100.0 g CuF2 ( 1 mol / 101.543 g) = 0.98 mol CuF2</span>
Answer:
17.5 g
Explanation:
Given data
- Mass of solution to be prepared: 50.0 grams
- Concentration of the salt solution: 35.0%
The concentration by mass of NaCl in the solution is 35.0%, that is, there are 35.0 grams of sodium chloride per 100 grams of solution. We will use this ratio to find the mass of sodium chloride required to prepare 50.0 grams of a 35.0% salt solution.
We are provided with the amount of energy released when one mole of carbon reacts. We mus first convert the given mass of carbon to moles and then compute the energy released for the given amount.
Moles = mass / atomic mass
Moles = 23.5 / 12
Moles = 1.96 moles
One mole releases 394 kJ/mol
1.96 moles will release:
394*1.96
= 772.24
The enthalpy change of the reaction will be -772.24 kJ
