How many moles of mgci2 are there in 310 g of the compound? this question is not multiple choice. i have two blank boxes to put my answer in, one that says answer and the other one is labeled units.

Number of Moles are calculate by using following formula,

                                        Moles  =  Mass / M.mass     --- (1)

M.mass is calculated by adding the atomic masses of all elements present in molecule, Since, MgCl₂ contains one Mg (atomic mass = 24.3 g/mol) and two Cl atoms (atomic mass = 35.45 × 2 = 70.9 g/mol), So,

                            Molar mass = 24.3 g/mol  +  70.9 g/mol

                            Molar Mass of MgCl₂ = 95.2 g/mol

Now, putting values in eq. 1,

                                        Moles  = 310 g ÷ 95.2 g/mol

                                        Moles  = 3.256 moles

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on