5 is the atomic number, 11 is the atomic mass and boron is the element
Answer:
The fraction of water body necessary to keep the temperature constant is 0,0051.
Explanation:
Heat:
Q= heat (unknown)
m= mass (unknown)
Ce= especific heat (1 cal/g*°C)
ΔT= variation of temperature (2.75 °C)
Latent heat:
ΔE= latent heat
m= mass (unknown)
∝= mass fraction (unknown)
ΔHvap= enthalpy of vaporization (539.4 cal/g)
Since Q and E are equal, we can match both equations:

Mass fraction is:


∝=0,0051
The balanced chemical reaction is written as:
<span>NaOH + HCl → NaCl + H2O
We are given the amount of sodium hydroxide to be used up in the reaction. This will be the starting point for the calculation.
2.75 x 10^-4 mol NaOH ( 1 mol H2O / 1 mol NaOH ) ( 18.02 g H2O / 1 mol H2O ) = 4.96 x 10^-3 g H2O</span>
The one that starts with c that is also the one that is anwser number c which is a