A piece of alloy of gold and silver weighs 2 kg in air and 1.86 kg in water. What is the mass of silver? Density of gold is 19.3 xx 10^(3)kgm^(-3). Density of silver is 10.5 xx 10^(3)kg m^(-3)

A piece of alloy of gold and silver weighs 2 kg in air and 1.86 kg in

1.	A piece of alloy of gold and silver weighs 2 kg in air and 1.86 kg in water. What is the mass of silver? Density of gold is 19.3 xx 10^(3)kgm^(-3). Density of silver is 10.5 xx 10^(3)kg m^(-3)
Answer» Solution :` "" ` Mass of silver = m Volume of silver `= ( " mass")/(" density ") ` ` "" = ( m)/( 10.5 XX 10 ^(3))` Mass of gold ` = 2-m ` Volume of gold = ` (2-m)/( 19.3 xx 10 ^(3)) ` TOTAL volume of alloy` (m)/(10.5 xx 10 ^(-3)) +(2-m)/( 19.3 xx 10 ^(3))` ` "" = [( m)/( 10.5)+(2-m)/(19.3) ]xx (1)/(10 ^(-3))` LOSS of weight of alloy in water = weight of water displaced ` "" = 0.14 = V xx D ` `0.14 = [(m)/( 10.5 ) +( 2-m)/( 19.3) ] xx (1)/( 10 ^(3)) xx 10 ^(3)` ` "" =( 19.3 m +10.5 xx 2 - 10 .5 m )/( 10.5 xx 19.3) ` ` 0 .14 xx 10 . 5 xx 19.3 = 8.8 m + 21` ` m= (0.14 xx 10 . 5 xx 19.3 -21 ) /( 8.8 ) ` ` "" = 0. 8376 kg`