Frequency is defined as the number of waves per second. In this machine 25 waves pass in one second.

We need to calculate the number of waves that pass a particular point during one second.

During 2 seconds -25 waves

Therefore in one second - 25/2 = 12.5 waves/s.

1 wave per second has the unit Hertz (Hz)

Therefore answer is 12.5 Hz

Boiling point is the only answer that doesn’t have to do with their physical property

**Answer:**

V = 48.5 L

**Explanation:**

Converting °C to K and kPa to atm

T = 25.0°C + 273.15 = 298.15 K

P = 61.3 kPa × (1 atm / 101.325 kPa) = 0.60498 atm

Calculating the volume of gas

V = nRT / P

V = (1.20 mol)(0.082057 L•atm/mol•K)(298.15 K) / 0.60498 atm

V = 48.5 L

Volume of Hydrogen V1 = 351mL

Temperature T1 = 20 = 20 + 273 = 293 K

Temperature T2 = 38 = 38 + 273 = 311 K

We have V1 x T2 = V2 x T1

So V2 = (V1 x T2) / T1 = (351 x 311) / 293 = 372.56

Volume at 38 C = 373 ml

The compound contains an **ester** functional group.

An ester is a carbonyl (C=O) group with an alkyl (R) group on one side and an alkoxy (OR) group on the other.

We write the <em>**condensed structural formula**</em> of an ester as R(C=O)OR or RCOOR.