D Microscopes
because they use them for DNA
a,b,and c, all you an item that can be used and not tested with.
Answer:
The answer to your question is m = 1.6
Explanation:
Data
mass of NaCl = 111 g
volume of water = 1.2 L
Molality = ?
Formula
Molality = number of moles / volume (L)
Process
1.- Calculate the moles of NaCl
Molecular mass = 23 + 35.5 = 58.5 g
1 mol of ------------------- 58.5 g
x -------------------- 111 g
x = (111 x 1) / 58.5
x = 1.897 moles of NaCl
2.- Calculate the mass of water
density of water = 997 kg/m³
mass = volume x density
mass = 0.0012 x 997
mass = 1.19 kg
3.- Calculate molality
m = 1.897/1.19
m = 1.6
The question has missing information! But, with the objects and their respectives masses and specific coefficiets and with the following explanation, the question can be aswered!
Answer:
The one which has the highest product of the mass by specific heat.
Explanation:
The heat is a way of "energy in motion", which means that is a way that energy can be exchanged between substances. This exchange occurs when there is a difference in the temperature of the substances that are in contact, and then, to achieve thermal equilibrium, one substance loses heat (the one with higher temperature) and had a decrease in temperature, and the other gain heat and had an increase of temperature.
The heat loss is the same heat gained, and it can be calculated. If the substance doesn't suffer a physical change (which is the case here), then:
Q = m*c*ΔT
Where Q is the heat, c is the specific heat, and ΔT is the temperature change. So, rearranged the expression:
ΔT = Q/(m*c)
Because Q is the same for all of the objects, the one that will experience the smallest temperature change is the one that has the highest value of m*c (because it is indirectly proportional to ΔT).
