Answer:
m = 4450 g
Explanation:
Given data:
Amount of heat added = 4.45 Kcal ( 4.45 kcal ×1000 cal/ 1kcal = 4450 cal)
Initial temperature = 23.0°C
Final temperature = 57.8°C
Specific heat capacity of water = 1 cal/g.°C
Mass of water in gram = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 57.8°C - 23.0°C
ΔT = 34.8°C
4450 cal = m × 1 cal/g.°C × 34.8°C
m = 4450 cal / 1 cal/g
m = 4450 g
Answers and explanation:
The factor label method, also known as dimentional analysis, is a way to do conversions.
To do it you use fractions with units, for example this is how you would do question one:
20 mL × 
= 0.02 L
Since 1L = 1000mL, we put the fraction . The litres are on top because they are the unit we want, while the mL are on the bottom so that they will cancel out. Certain questions may require more than one step of this.
We can use this same method with all the other questions:
2. 950 g × 
= 0.95 kg
3. 55 mm × 
= 0.055 m
4. 200 in × 
= 508 cm
5. 25 cm × 
= 250 mm
6. 0.005 kg × 
= 0.5 dag
7. 2 hrs × 
= 7200 s
8. 15 g × 
= 15000 mg
9. 1.3 yrs × 
× 
= 11388 hrs
10. 0.075 m × 
= 7.5 cm
Enzymes affect the rate of the reaction in both the forward and reverse directions; the reaction proceeds faster because less energy is required for molecules to react when they collide. Thus, the rate constant (k) increases. Figure 3: Lowering the Activation Energy of a Reaction by a Catalyst.
hope this helps!
(:
Answer:
1.65hr
Explanation:
Given parameters:
Number of labs = 5 labs
Time taken = 3 minutes
Unknown:
Time taken in hours to grade 165 labs = ?
Solution:
Let us find the rate of the teacher;
Rate = 
Insert the parameters and solve;
Rate = 
= 1.67labs/min
Now;
Time to grade 165 labs = 
Time to grade 165 labs = 
= 98.8min
Since;
60min = 1hr
98.8min = 
= 1.65hr
Answer:
The pressure will be doubled.
