A single fixed pulley is used to lift load by changing the direction of the lifting force. Even though a single fixed pulley has no mechanical gain in that, the effort applied is greater than the load, it is preferred in use since you do not have to pull or push the pulley up and down.
Answer:
probably because most of our food comes from animals-
Explanation:
Answer:
b. ΔE rxn is a measure of heat
Explanation:
a. ΔHrxn is the heat of reaction. <em>TRUE. </em>ΔHrxn or change in enthalpy of reaction is per definition the change in heat that is involved in a chemical reaction.
b. ΔErxn is a measure of heat. <em>FALSE. </em>Is the change in internal energy of a reaction
c. An exothermic reaction gives heat off heat to the surroundings. <em>TRUE</em>. An exothermic reaction is a chemical reaction that releases heat.
d. Endothermic has a positive ΔH. <em>TRUE. </em>When a process is exothermic ΔH<0 and when the process is endothermic ΔH>0
e. Enthalpy is the sum of a system's internal energy and the product of pressure and volume. <em>TRUE. </em>Under constant pressure and volume the formula is ΔH = ΔE + PV
I hope it helps!
The magnesium dissolves to form magnesium chloride and hydrogen gas is released.
Mg + 2HCl -----> MgCl2 + H2(g).