0.448 moles of ions will form when a 42.66-gram sample of magnesium chloride is dissolved in water (option A).
<h3>How to calculate number of moles?</h3>
According to this question, when magnesium chloride (MgCl2) dissolves in water, it dissociates into magnesium ions and chloride ions as follows:
MgCl2(aq) ⟶ Mg2+(aq) + Cl−(aq)
However, if a 42.66-gram sample of magnesium chloride is dissolved in water, this means that 42.66g/molecular mass of MgCl2 will be the number of moles of the ionic products.
molecular mass of MgCl2 = 95.3g/mol
moles = 42.66g ÷ 95.3g/mol = 0.448mol
Therefore, 0.448 moles of ions will form when a 42.66-gram sample of magnesium chloride is dissolved in water.
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Answer:
ºC
Explanation:
We have to start with the variables of the problem:
Mass of water = 60 g
Mass of gold = 13.5 g
Initial temperature of water= 19 ºC
Final temperature of water= 20 ºC
<u>Initial temperature of gold= Unknow</u>
Final temperature of gold= 20 ºC
Specific heat of gold = 0.13J/gºC
Specific heat of water = 4.186 J/g°C
Now if we remember the <u>heat equation</u>:


We can relate these equations if we take into account that <u>all heat of gold is transfer to the water</u>, so:

Now we can <u>put the values into the equation</u>:

Now we can <u>solve for the initial temperature of gold</u>, so:

ºC
I hope it helps!
Plasma membrane is the answer
Exothermic reaction is where there is release of energy during a reaction
The enthalpy of exothermic reaction is negative
The relation between energy of products, reactants and enthalpy of reaction is
Enthalpy of reaction = sum of enthalpy of formation of products - sum of enthalpy of formation of reactants
.
As enthalpy of reaction is negative, it means the enthalpy of products is less than the enthalpy of reactants so answer is
:
In an exothermic reaction the energy of the product is less than the energy of the reactants.
Since both atoms are the same and are both nonmetals, they would form a Nonpolar covalent bond. This bond occurs when usually atoms of the same element or atoms of propriety electronegativity differences are sharing electrons to form bonds. There is an equal sharing of valence electrons in this chemical bond.