Answer:
the heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).
The correct answer is B,
<span>It is endothermic, with both positive enthalpy and entropy changes.</span>
Answer:
6.25 μg/mL
Explanation:
When a dilution is made, the mass of the solute is conserved (Lavoiser's law), so the mass pipetted will be the mass in the assay. The mass is the concentration (C) multiplied by the volume (V). If the pipet solution is called 1, and the assay 2:
m1 = m2
C1*V1 = C2*V2
C1 = 250 μg/mL
V1 = 25 μL
V2 = 975 μL + 25 μL = 1000 μL (is the final volume of the assay after the addition of LDH)
250*25 = C2*1000
C2 = 6.25 μg/mL
You have to switch the elements based in if they're metals/nonmetals. so nonmetals switch with each other and metals switch with each other.
AB + CD ---> AC + BD
The question is incomplete, the complete question is:
Which statements are consistent with Dalton's atomic theory as it was originally stated? Why?
a. Sulfur and oxygen atoms have the same mass.
b. All cobalt atoms are identical.
c. Potassium and chlorine atoms combine in a 1:1 ratio to form potassium chloride.
d. Lead atoms can be converted into gold.
<u>Answer: </u>The correct options are b) and c).
<u>Explanation:</u>
Some of the postulates of Dalton's atomic theory are:
- All matter is made of very tiny particles called atoms that participate in chemical reactions
- Atoms are indivisible particles that cannot be created or destroyed in a chemical reaction
- Atoms of a given element are identical in mass and chemical properties
- Atoms of different elements have different masses and chemical properties.
- Atoms combine in the ratio of small whole numbers to form compounds.
- The relative number and kinds of atoms are constant in a given compound.
For the given options:
<u>For a:</u>
The statement is inconsistent with the theory as no two elements can have the same mass. Only atoms of the same element can have the same mass.
This is consistent with the theory as atoms of the same element are identical.
This is consistent with the theory as atoms combine in a simple whole number ratio.
The statement is inconsistent with the theory as atoms of one element cannot be changed to atoms of other element.
Hence, the correct options are b) and c).
