Answer:
B. is the answer
Explanation:
Energy in form of heat is transferred from the warmer mashed potatoes to the cooler spoon.
The number of moles of moles of Magnesium,chlorine and oxygen atoms in 7.80 moles of Mg(ClO4)2 is calculated as below
find the total number of each atom in Mg(ClO4)2
that is mg = 1 atom
Cl = 1x2 = 2 atoms
O = 4 x2 = 8 atoms
then multiply 7.80 moles with total number of each atom , to get the number moles of each atom
that is
Mg = 7.80 x1= 7.80 moles
cl = 7.80 x2=15.6 moles
O = 7.80 x8= 62.4 moles
Answer:
A) Ca(s) + C(s) + 3/2 O₂(g) → CaCO₃(s)
Explanation:
Standard enthalpy of formation of a chemical is defined as the change in enthalpy durin the formation of 1 mole of the substance from its constituent elements in their standard states.
The consituent elements of calcium carbonate, CaCO₃, in their standard states (States you will find this pure elements in nature), are:
Ca(s), C(s) and O₂(g)
That means, the equation that represents standard enthalpy of CaCO₃ is:
<h3>A) Ca(s) + C(s) + 3/2 O₂(g) → CaCO₃(s)</h3><h3 />
<em>Is the equation that has ΔH° = -1207kJ/mol</em>
Atomic mass number is the number of protons and neutrons. Subtract 80-35=45 is the number of protons. Because the atom is neutrally charged, the number of protons must equal the number of electrons, so there are 45 electrons.