a) H_(2)SO_(4)(p)+Ca= 6) H_(2)SO_(4)(p)+K_(2)O= r) H_(2)SO_(4)(p)+Ba(NO_(3))_(2)= II) H_(2)SO_(4)(K)+K=

a) $H_{2}SO_{4}(p)+Ca=$<br />$H_{2}SO_{4}(p)+Ca\rightarrow CaSO_{4}+H_{2}\uparrow$<br /><br />6) $H_{2}SO_{4}(p)+K_{2}O=$<br />$H_{2}SO_{4}(p)+K_{2}O\rightarrow K_{2}SO_{4}+H_{2}O$<br /><br />r) $H_{2}SO_{4}(p)+Ba(NO_{3})_{2}=$<br />$H_{2}SO_{4}(p)+Ba(NO_{3})_{2}\rightarrow BaSO_{4}\downarrow+2HNO_{3}$<br /><br />II) $H_{2}SO_{4}(K)+K=$<br />$H_{2}SO_{4}(K)+K\rightarrow K_{2}SO_{4}+H_{2}\uparrow$