What is the percent yield when 1.72 g of H2O2 decomposes and produces 375 mL of O2 gas measured at 42 oC and 1.52 atm

87.0%

Explanation:

Step 1: Write the balanced reaction

H₂O₂ ⇒ H₂O + 0.5 O₂

Step 2: Calculate the real yield of oxygen, in grams

We have 375 mL (0.375 L) of O₂ at 42 °C (315 K) and 1.52 atm. First, we will calculate the number of moles using the ideal gas equation.

P × V = n × R × T

n = P × V / R × T

n = 1.52 atm × 0.375 L / (0.0821 atm.L/mol.K) × 315 K = 0.0220 mol

The molar mass of oxygen is 32.00 g/mol.

0.0220 mol × 32.00 g/mol = 0.704 g

Step 3: Calculate the theoretical yield of oxygen, in grams

According to the balanced equation, the mass ratio of H₂O₂ to O₂ is 34.01:16.00.

1.72 g H₂O₂ × 16.00 g O₂/34.01 g H₂O₂ = 0.809 g O₂

Step 4: Calculate the percent yield of oxygen

We will use the following expression.

%yield = real yield / theoretical yield × 100%

%yield = 0.704 g / 0.809 g × 100% = 87.0%

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

the answer is definitely c.