What is the mass, in grams, of each elemental sample? a. 2.3 * 10-3 molSb b. 0.0355 mol Ba c. 43.9 mol Xe d. 1.3 mol W

a. Sb =0.280048 g ,  b. Ba=4.875215 g ,  c.  Xe=5763.631 g ,    d. W=238.992 g

Explanation:

number of moles =

(a) For Sb, molar mass =121.76g/mol

number of moles =2.3*mol

mass= number of moles * molar mass

mass =2.3* *121.76

mass =0.280048 g

(b) for Ba, molar mass=137.33 g/mol

number of moles =0.0355 mol

mass = 0.0355 *137.33

mas = 4.875215 g

(c) for Xe, molar mass = 131.29 g/mol

number of moles =43.9 mol

mass =43.9 *131.29

mass =5763.631 g

(d) for W, molar mass = 183.84 g/mol

number of moles = 1.3mol

mass = 1.3 *183.84

mass = 238.992 g

93.2 ml + 3920 ml = 4013 ml total  

(93.2 ml) * (2.03 m) / (4013 ml) = 0.0471 m

the volume in in l of the diluted solution would be 0.0471 m.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.