Question

You are breathing at a rate of 20 breaths per minute in a warm, dry environment.

Each time you take a breath, you breathe in 0.5×10−3 kg of air at a temperature of 24°C and with a relative humidity of 20%. You breathe out the same mass of air but at a temperature of 36°C and a relative humidity of 100%.

How much water vapour do you exhale in one hour under these circumstances? (to 2 s.f and in g)

Answer 1

In one minute 20 breathing takes place

so in 1 hour (60 minutes) no. of breathing = 60$\times$20=1200

As we are inhaling air with 20 % humidity and exhaling with 100% which means 80% increase in humidity takes place

water vapor exhaled in 1 hour=$1200\times \frac{80}{100}\times 0.5\times10^{-3}kg=0.48 kg$