A cold front is the leading edge of a cooler mass of air, replacing at ground level a warmer mass of air, which lies within a fairly sharp surface trough of low pressure.
Answer: There are now 2.07 moles of gas in the flask.
Explanation:
P= Pressure of the gas = 697 mmHg = 0.92 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = ?
n = number of moles = 1.9
T = Temperature of the gas = 21°C=(21+273)K= 294 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
When more gas is added to the flask. The new pressure is 775 mm Hg and the temperature is now 26 °C, but the volume remains same.Thus again using ideal gas equation to find number of moles.
P= Pressure of the gas = 775 mmHg = 1.02 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = 49.8 L
n = number of moles = ?
T = Temperature of the gas = 26°C=(26+273)K= 299 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
Thus the now the container contains 2.07 moles.
Your answer is B, conservation of mass
Recall that percent yield is given by: %Yeild = actual yeild/theoretical yeild x100
During experiments, there are errors made:
• uncertainty in measurements
• losses of reactants and products
• impurity in reactants
• losses during separation (e.g. filtration or purification)
• Some side reactions might also happen.
Among the given options, only conservation of mass does not contribute to a lower actual yield compared to the theoretical yield.
Answer:
19.8 %
Explanation:
V% = ( V of solute \ 100 ml of solution ) ×100% =
the volume of the solute in 100ml solition = 20 ml
42.9 ml of solute ----------215 ml solution
× ----------- 100 ml solution
42.6 × 100 ml ÷ 215 ml
= 19.8 ml of solute
the V% = (19.8 ÷ 100) ×100% = 19.8%
Answer:
The answer is 0.844/10 minutes
Explanation:
You have an enzyme that catalizes a reaction which gives a product that can be quantified by an absorbance measurement. The more reaction time, the more product quantity and higher absorbance.
The rate of the reaction is the change in products quantity per time unit. As you are using the absorbance as a measure of the product quantity, you can calculate the rate as the change in absorbance (ΔA) per time (in minutes) as follows:
rate= ΔA/time
rate= (final absorbance - initial absorbance) /minutes
rate= (0.444-0.022)/5 min
rate= 0.422/5 min
In 10 minutes will be :
rate= 0.844/10 min
Commonly, a rate is the relation between two quantities measured in different units. For example, the speed of a car is the change in meters (traveled distance) per time (m/s or km/h). For an enzyme, is the same (quantity of product/time).
