A relative density bottle has a mass of 19 g when empty. When it is

Explanation

Let mb=mass of empty bottle,

\(m_w\)=mass of water only and

\(m_a\)= mass of alcohol only

given; \(m_b\)=19g

\(m_b\) + \(m_w\) = 66g

\(m_b\) + \(m_a\) = ?

R.d=0.8

R.d=mass of alcohol

⇒\(\frac{mass of alcohol}{mass of equal volume of water}\)

⇒ mass of equal volume of water = \(m_w\)=66-19=47g

⇒0.8 = \(\frac{m_a}{47}\)

⇒\(m_a\)=0.8×47 =37.6g

; \(m_b\) + \(m_a\) = 19+37.6=56.6g