Q=mc(deltaT)
Q is the amount of energy which you are looking for
M is the mass which you can find
C is the specific heat of water which is 4.18 J/gC
DeltaT is the change in temperature which you can find.
To find the mass, first you must know that the density of water is 1g/mL, meaning that 200 mL has a mass of 200 g. This means that to find the total mass (m in the equation) all you need to do is add the mass of water and NaOH.
200 g + 2.535 g=202.535 g.
To find deltaT you would need to take the final temperature minus the initial temperature.
27.8C-24.2C=3.6C
Then these values can be substituted into the equation:
q=(202.635g)(4.18J/gC)(3.6C)
Q=3049.25 J
Technically this should be rounded off to 1 significant figure (200 mL only had 1), but ignoring signficiant figure rules this should be correct. Also, sometimes other units like calories or kJ may be asked for, meaning that a conversion or alternate c value would be used.
<span> under extreme heat or pressure
crystallize from magma
precipitate from a solution reaction of hot mixture with water and a dissolved substance</span>
Q: What is the change of entropy for 3.0 kg of water when the 3.0 kg of water is changed to ice at 0 °C? (Lf = 3.34 x 105 J/kg)
Answer:
-3670.33 J/K
Explanation:
Entropy: This can be defined as the degree of randomness or disorderliness of a substance. The S.I unit of Entropy is J/K.
Mathematically, change of Entropy can be expressed as,
ΔS = ΔH/T ....................................... Equation 1
Where ΔS = Change of entropy, ΔH = heat change, T = temperature.
ΔH = -(Lf×m).................................... Equation 2
Note: ΔH is negative because heat is lost.
Where Lf = latent heat of ice = 3.34×10⁵ J/kg, m = 3.0 kg, m = mass of water = 3.0 kg
Substitute into equation
ΔH = -(3.34×10⁵×3.0)
ΔH = - 1002000 J.
But T = 0 °C = (0+273) K = 273 K.
Substitute into equation 1
ΔS = -1002000/273
ΔS = -3670.33 J/K
Note: The negative value of ΔS shows that the entropy of water decreases when it is changed to ice at 0 °C
Answer:
25 mph
Explanation:
So we have to find the unit rate, or you could use the DTS triangle, but both say you have to divide, so our equation is:
176 ÷ 7 = 25.14
But I'm going to round that
So the train is traveling at 25 mph
hope this helps:/
