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:
Weathering, Erosion
Explanation:
Plants and animals can be agents of mechanical weathering. The seed of a tree may sprout in soil that has collected in a cracked rock. As the roots grow, they widen the cracks, eventually breaking the rock into pieces. Over time, trees can break apart even large rocks.
Tree root systems have a handful of large roots that branch out into a network of smaller roots that often extend out far beyond their branches do. These root systems prevent erosion by holding the soil in place and improving drainage which helps water get absorbed into the soil instead of just running over the top.
Hope this helps
All the love, Ya boi Fraser :)
Answer:24.31
Explanation:Contribution made by isotope of mass 23.99= 23.99×78.99=1894.97
Contribution made by isotope of mass 24.99=24.99×10.00=249.9
Contribution made by isotope of mass 25.98=25.98×11.01=286.04
Total contribution=1894.97+249.9+286.04=2430.91
Average mass=2430.91÷100
=24.31
<span>Gloria is writing the
chemical formula for a compound using its chemical name. She has just
identified the names of the elements in the compound. The tool that she will
need to use next is a textbook to learn the IUPAC naming of compounds or a
handbook of chemical compounds.</span>
First one - Mg(OH)2+2HCl— MgCl2+ 2H2O
second one - CH4+2O2– 2H20
Third- is already balanced.
