When 2.50 g of a certain hydrocarbon was completely combusted in a "bomb (constant-volume) calorimeter" with a heat capacity (excluding water) of 350 j/°c and which contained 2.00 liters of water (density = 1.00 g/ml and specific heat capacity = 4.184 j/°c•g), the resulting temperature change was measured to be 5.52°c. calculate the thermal energy (in kj) released per gram of hydrocarbon combusted.(1) 48.1 kj/g (2) 0.773 kj/g (3) 19.2 kj/g (4) 18.5 kj/g (5) 46.2 kj/g

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.