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.
Answer:
boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At)
Explanation:
metalloids are elements that are in between the metals and nonmetals. they are in between because they have properties of both metals and nonmetals.
you can search "metalloids on the periodic table" and go to images to see what i mean :)
Answer: A. is prey B. is predator C. is habitat D. is comunity E. is plants are producers and plant eating animals consumors F. is food chain G. is food web H. parasite I decomposers and scavengers J. is compete K an adsption
Explanation:
First. let's write the reaction formula: HBr +LiOH ----> LiBr + H₂O
let's get the moles of LiOH first
moles= Molarity x Liters
moles= 0.253 M x 0.01673 Liter= 0.00423 moles LiOH
using the balanced equation, you can see that 1 mol LiOH is equal to 1 mol HBr. so:
0.00423 mol LiOH = 0.00423 mol HBr
now let's find the concentration
molarity= mol/ Liters
0.00423 mol/ 0.01000 Liters= 0.423 M
Answer:
Option a. 0.5 m/s
Explanation:
This graph shows a straight line, where "Y" axis would be "Position" and "X" graph would be "Time". The ecuation that would describe this straight line is Y= aX + 1 , where "a" is the slope or inclination for this graph, and would give us the speed of the object
How do we find the slope (and hence, the speed)?: if you notice this graph, you will check that:
-When X (Time) is zero, Y (Position) is 1
-When X (Time) is 2, Y (Position) is 2
With these 4 points, you can calculate the slope (which will call "m") for this graph with:
m = (Y2-Y1)/(X2-X1) so: Y2=2, Y1=1, X2=2, X1=0
Which gives us: m=1/2 (0.5), the slope or speed of the object: 0.5 m/s
