Question

The mass % of NAOH is 5 molal aqueous Naoh solution is ( atomic weight of Na = 23) 1} 18% 2} 20% 3}16.7% 4)18.6%

Answer 1

Given:

The molality of NaOH solution, m = 5 m

To Find:

The mass percent of NaOH in the solution.

Calculation:

- 5 molal aqueous solution of NaOH means 5 moles of NaOH are dissolved in 1 kg water.

- So, the mass of 5 moles of NaOH, w = 5 × 40 = 200 gm

- The total mass of solution, W = mass of water + mass of NaOH

⇒ W = 1000 + 200 = 1200 gm

- Mass percent = (w/W) × 100

⇒ Mass percent = (200/1200) × 100

⇒ Mass percent = 16.7 %

- S0, the correct answer is option (3) 16.7 %.

Answer 2

Explanation:

सिलेंडर इनकरेक्ट स्टेटमेंट ऑफ द फॉलोइंग कंपाउंड फॉर्म एलिमेंट यूज्ड सेकंड कांस्टीट्यूएंट आफ कंपाउंड कैंडी सेपरेटेड इनटू सिंपल सेंटेंसेस बाय फिजिकल मेथड