Как построить тризвучия, в Соль-мажоре?

mark and he are thirteen years old.and they are very sportly. they often go to the gym - at least three times a week. mark does exercises to make his arms strong. he can't walk because of a car accident, so he goes everywhere in wheelchair. but it doesn't stop him doing the things that boys his age want to do.

3) пианино, фортепиано

  bacl2 + h2so4 = baso4 + 2hcl

найдем массу серной кислоты m=200 *0.1225= 24.5 г

ищем кол-во вещ-ва серной к-ты =24.5 \98= 0.25 по уравнению кол-во вещ-ва серной кислоты и сульфата бария равны значит кол-во вещества baso4=0.25

найдем массу baso4 m= кол-во вещ-ва * m= 208 * 0.25=   52г 

не забываем жмакать )