Answer:
Explanation:
q= mc theta
where,
Q = heat gained
m = mass of the substance = 670g
c = heat capacity of water= 4.1 J/g°C
theta =Change in temperature=(
66-25.7)
Now put all the given values in the above formula, we get the amount of heat needed.
q= mctheta
q=670*4.1*(66-25.7)
=670*4.1*40.3
=110704.1
The oxidation number of iodine is 5 in Mg(IO3)2 which can be calculated as
Mg(IO3)2
MgI2O6
As we know that
Mg has +2
O has -2
So,
(+2) + 2I + 6 (-2)=0
2 + 2I - 12 =0
10+ 2I =0
10 = 2I
I =5
Answer:
A = 679.2955 ppm
Explanation:
In this case, we already know that 64Cu has a half life of 12.7 hours. The expression to use to calculate the remaining solution is:
A = A₀ e^-kt
This is the expression to use. We have time, A₀, but we do not have k. This value is calculated with the following expression:
k = ln2 / t₁/₂
Replacing the given data we have:
k = ln2 / 12.7
k = 0.0546
Now, let's get the concentration of Cu:
A = 845 e^(-0.0546*4)
A = 845 e^(-0.2183)
A = 845 * 0.8039
A = 679.2955 ppm
This would be the concentration after 4 hours
The correct answer is Hot water increases the collision rate of molecules, causing the reaction to occur faster.
Explanation:
Temperature is directly related to the kinetic energy or movement of molecules in a substance. In this context, a higher temperature leads to more kinetic energy or more collision between molecules. At the same time, a chemical reaction involves molecules of two or more substances colliding and creating bonds to form new substances. This implies an increase in temperature means molecules colliding faster, new substances forming in a shorter time, and therefore a faster chemical reaction. According to this, the first answer is correct.
The equation of the chemical reaction is NaHCO3 + H+ --> H2O + CO2 + Na
To determine the total number of moles of carbon dioxide, the given mass of sodium hydrogen carbonate is divided with its own molar mass. Then it is multiplied with the ratio between NaHCO3 and carbon dioxide. The total number of moles of CO2 one tablet should yield is 0.024 mole.
