Answer:
C )
Explanation:
Controlled scientific experiment tests scientific assumption (hypothesis), under controlled conditions.
In controlled scientific experiment, alters the test variable (independent variable) and observes the effects on the outcome variable (dependent variable).
Eg : Studying impact of sunlight on plant's group, where former independent variable is altered & its effects on dependent outcome variable is observed.
Answer:
When popcorn is popped, liquid inside the kernel is changed to steam. Pressure from the steam builds up inside the kernel. When the pressure reached a critical stage the kernel pops turning itself inside out. This is a physical change.
Explanation:
Answer:
4 moles of water
Explanation:
this is a combustion reaction, so the balanced equation is: 2C2H6 + 7O2 → 4CO2 + 6H2O.
the molar mass of C2H6 is 30.07g, so 40.0 g of C2H6 is 1.33 moles of C2H6.
mole ratio of H2O to C2H6 is 6/2, or 3.
1.33 moles C2H6 * 3 moles H2O/1 mole C2H6 = 4 moles H2O
Answer:
-125.4
Explanation:
Target equation is 4C(s) + 5H2(g) = C4H10
These are the data equations for enthalpy of combustion
- C(s) + O2(g) =O2(g) -393.5 kJ/mol * 4
- H2(g) + ½O2(g) =H20(l) = 285.8 kJ/mol * 5
- 2CO2(g) + 3H2O(l) = 13/2O2 (g) + C4H10 - 2877.1 reverse
To get target equation multiply data equation 1 by 4; multiply equation 2 by 5; and reverse equation 3, so...
Calculate 4(-393.5) + 5(-285.8) + 2877.6 and you should get the answer.
