Calculate the standard enthalpy change for the reaction 2a+b⇌2c+2d use the following data: substance δh∘f (kj/mol) a -269 b -419 c 205 d -515 for the reaction given in part a, how much heat is absorbed when 3.10 mol of a reacts?

The volume of a sphere is given by v= (4/3) pi r cubed, where r is the radius. compute the volume of a sphere with a radius of 117pm. state your answer in units of cubed.

Which of the following statements is not true? • a. covalent compounds have low melting and boiling points. • ob. covalent bonds between atoms of a compound are relatively weak compared to bonds between molecules. • c. covalent bonds occur between nonmetals. • d. covalent compounds are often gases or liquids.

In this synthesis reaction what products will form