The stock solution contains 10.5 moles of HCl per litre. A 5.5 litre solution of 2.5M HCl contains 5.5x2.5 = 13.75moles of HCl. Since every litre of stock solution provides 10.5M HCl, the amount of stock solution needed is 13.75/10.5 = 1.309L. Therefore you would dilute 1.309L of stock solution to 5.5L
Coal falls under Graphite
Explanation
NaCl: Ionic crystal lattice forces
Hg: Metallic bonding
CO₂: London dispersion forces
CH₄: London dispersion forces
Li₂O: Ionic crystal lattice forces
Ag: Metallic bonds
Ionic crystal lattice forces are strong electrostatic force of attraction between oppositely charged ions arranged into a crystal lattice of ionic compound. NaCl and Li₂O are ionic compounds
London dispersion forces holds the molecules of carbon dioxide and methane. They are weak attractions found between non-polar (and polar) molecules.
Metallic bonds exists between Mercury and Gold atoms. This is due to sea of electrons present.
Explain whether this is a chemical or physical change, and why. does it involve elements, compounds, mixtures, or pure substances?
If the process involves a chemical reaction then surely it is a chemical change where new bonds are being formed from the collision of the reactants.
Describe how many atoms are involved before and after. what do you notice about the number of atoms?
From the balanced chemical reaction, we see that we need 1 mol of N2 gas and 3 mol of H2 in order to form 2 mol of NH3.
