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!
Answer:
like how do you need help
Answer:
A sample of an ideal gas has a volume of 2.21 L at 279 K and 1.01 atm. Calculate the pressure when the volume is 1.23 L and the temperature is 299 K.
You need to apply the ideal gas law PV=nRT
You have the pressure, P=1.01 atm
you have the volume, V = 2.21 L
The ideal gas constant R= 0.08205 L. atm/ mole.K at 273 K
find n = PV/RT = (1.01 atm x 2.21 L / 0.08205 L.atm/ mole.K x 273 K)
n= 0.1 mole, Now find the pressure for n=0.1 mole, T= 299K and
L=1.23 L
P=nRT/V= 0.1mole x 0.08205 (L.atm/ mole.K x 299 k)/ 1.23 L
= 1.994 atm
Explanation:
Answer:
2-4 mm height of capillary tube.
Explanation:
Sample should be around 2-4 mm in height.
It should be packed well so that it does not have air packets that caues the lowering of melting point.
If you take greater amount, then there will be needed more heat, resulting a wide range of melting point.
Depending upon the clumping reaction with anti A , anti B and anti Rh antibodies the blood types are determined.
Explanation:
Agglutination (clumping) will occur when blood that contains the particular antigen is mixed with the particular antibody.
A+ have Agglutination with Anti-A ,Anti-Rh and No agglutination with Anti-B.
A- have Agglutination with Anti-A and No agglutination with Anti-B and Anti-Rh.
B+ have Agglutination with Anti-B Anti-Rh and No agglutination with Anti-A.
B- have Agglutination with Anti-B and No agglutination with Anti-B and Anti-Rh.
Rh+ have Agglutination with Anti-A and Anti-Rh and No agglutination with Anti-B.
Rh- have No Agglutination with Anti-A and Anti-B and Anti-Rh.
