Answer:
-26.125 kj
Explanation:
Given data:
Mass of water = 250.0 g
Initial temperature = 30.0°C
Final temperature = 5.0°C
Amount of energy lost = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 5.0°C - 30.0°C
ΔT = -25°C
Specific heat of water is 4.18 j/g.°C
Now we will put the values in formula.
Q = m.c. ΔT
Q = 250.0 g × 4.18 j/g.°C × -25°C
Q = -26125 j
J to kJ
-26125 j ×1 kj /1000 j
-26.125 kj
The metalloids are Boron, Silicon, Geranium, etc and are found to the right of the metals and the left of the nonmetals. Since that is not an option, the best choice would be: The metalloids are located below nonmetals and above metals within a group.
Answer:
Ba
Explanation:
<u>The elements Calcium ( Ca ) and Cobalt ( Co ) , are both present in the same period , and across the period the atomic radius decreases from left to right , since , the atomic number increases , so the electrons increases , which in turns increases the effective nuclear charge , and hence the size decreases , </u>
Therefore ,
Calcium will have bigger atomic radii as compared to Cobalt .
Now,
<u>The elements Barium ( Ba ) and Calcium ( Ca ) are , both are present in the same group , and down the group , atomic radii increases , since , as going down the group , the atomic number increase , so the shells increases , hence the size increases .</u>
Therefore , the atom with the largest radii is Barium .
Answer:
Molarity of solution is 1.10x10⁻³ M
Explanation:
Solute NaOCl
7.4% by mass means, that in 100 grams of solution, we have 7.4 g of solute.
Molar mass of NaOCl = 74.45 g/m
Mol = Mass / Molar mass
7.4 g / 74.45 g/m = 0.099 moles
Density of solution = 1.12 g/mL
Density = Mass / volume
1.12g/mL = 100 g / volume
Volume = 100 g / 1.12g/mL = 89.3 mL
Molarity = mol /L
89.3 mL = 0.0893 L
0.099 moles / 0.0893 L = 1.10x10⁻³ M
