Answer: 4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Explanation:
Temperature of Solid 
Melting temperature of Solid 
Temperature of liquid 
Specific heats of solid ethanol = 0.97 J/gK
Specific heats of liquid ethanol = 2.3 J/gK
Heat required to melt the the 25 g solid 
at 159 K
= 159 K - 138 K = 21 K
Heat required to melt and raise the temperature of upto 223 K
= 223 K - 159 K = 64 K
Total heat to convert solid ethanol to liquid ethanol at given temperature :
(1kJ=1000J)
Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Heat can be absorbed or produced
So the molarity equation is moles of solute/liters of solution. so i’m pretty sure the answer should be 0.63/0.70= .9
Answer:
44.9g
Explanation:
You have to convert grams of CH4 to moles, use the mole-to-mole ratio of CH4 to water, and convert back to grams.
(20.0g CH4)(1 mol CH4/16.04g)(2 mol H2O/1 mol CH4)(18.01 g H2O/ 1 mol) = 44.9127 g
Hope this helps!
Answer:
B. observing that a bone placed in a beaker of acid becomes bendy
Explanation:
The hypothesis suggests that when chicken bones are placed in vinegar, they become bendy due to the loss of calcium in their bones.
Calcium is identified as the ossifying material that strengthens the bone. When the acid that makes up the vinegar comes in contact with it, calcium is removed from the bone.
Now we know that calcium has capabilities of reacting with acids.
This suggests that if we also place the bone in an acid, they will bend due to reaction of calcium in the bones with the acid.
