Answer: 1709.4 Joules
Explanation:
The quantity of Heat Energy (Q) released on cooling a heated substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since Q = ?
M = 18.5 grams
Recall that the specific heat capacity of copper C = 0.385 J/g.C
Φ = 285°C - 45°C = 240°C
Then, Q = MCΦ
Q = 18.5grams x 0.385 J/g.C x 240°C
Q = 1709.4 Joules
Thus, 1709.4 Joules is released when copper is cooled.
The equation of 5m+4=7m+6 is equal to m=-1
Answer:Respuesta. El peso molecular de NaCl es 58gr que equivale a 1 mol. g? hay 0,5mol queda 29gr
Explanation:
We know that the element Z = 119 would be placed right below the Fr, in the column of the alcaline metals.
We also know that the trend in the electronegativity is to decrease when you go up-down ia group.
The known electronegativities of the elements of this group are:
Li: 0.98
Na: 0.93
K: 0.82
Rb: 0.82
Cs: 0.79
Fr: 0.70
Then the hypotetical element Z = 119 would probably have an electronegativity slightly below 0.70, for sure in the range 0.60 - 0.70.
In order to make the dissolution of the solid compound in water to occur at a faster rate, Samuel could do the following:
1. Break down the solid into tiny particles: breaking down the solid into tiny particles increases the surface area of the solid and thus increase the quantity of the substance that comes in contact with the solvent per time, this leads to a faster dissolution of the solid.
2. Stir the liquid with iron rod: Samuel can increase the dissolution rate of the substance by stirring it continuously with iron rod.
3. Increasing the temperature:Samuel could also increase the rate of dissolution of the substance by increasing the temperature of the water.