# Question #fb855

##### 1 Answer

Mar 15, 2016

#### Explanation:

- The equation is

#CaCO_3->CaO + CO_2# - Find the formula masses of
#CO_2# and#CaCO_3#

#CaCO_3# =#100# grams per mole

#Ca=1 # x# 40=40#

#C=1 # x# 12=12#

#O=3 # x# 16=48#

#CO_2# =#44# grams per mole

#C=1 # x# 12=12#

#O=2 # x# 16=32# - Find the mass of pure marble;

#mass pure=(actual mass)(purity)#

#mass pure=((10g)(0.50)#

#mass pure=5 g# - Convert mass
#CaCO_3# to mole#CaCO_3#

#5 cancel(g CaCO_3) # x# (1 mol CaCO_3)/(100 cancel(g CaCO_3)#

#0.05 mol CaCO_3# - Find the mol
#CO_2# ; referring to the equation it's observed that both compounds have same number of mole; thus

#CO_2=0.05 mol# - Convert
#250 ml# to Li;#0.25 Li# - Therefore, to find the Molarity(M) use the formula:

#M=(n. mol)/(Li solution)#

#M=(0.05 mol)/(0.25 Li)# #M=0.20 (mol)/(Li)# or#0.20M#