Its c ok im sorry if i got the last answer wrong
What amount of heat absorbs 50 g of steel (ce = 0.115 cal / g. ° C) that
does its temperature vary by 25 ° C?
Answer:
143.75cal
Explanation:
Given parameters:
Mass of steel = 50g
Specific heat capacity of the steel = 0.115cal/g°C
Temperature = 25°C
Unknown:
Amount of heat = ?
Solution:
The amount of heat to cause this temperature change is dependent on mass and specific heat capacity of the substance.
Amount of heat = m C (ΔT)
m is the mass
c is the specific heat capacity
ΔT is the temperature change
Now insert the parameters and solve;
Amount of heat = 50 x 0.115 x 25
Amount of heat = 143.75cal
Answer:A
Explanation:
The melting points of solids depend in the relative sizes of ions in the ionic lattice. The smaller the relative sizes of the ions, the higher the lattice energy and the stronger the lattice hence higher melting point. Comparing relative ionic sizes, fluoride ion is lesser in size than chloride ion hence NaF has a higher melting point than NaCl.
Answer:
241 nm, it is UV light range
Explanation:
The minimum energy needed required to break the oxygen-oxygen bond = 495 kJ/mol
Energy needed for 1 molecule of oxygen = 495 × 10³ J / avogadro's constant = 495 × 10³ J / ( 6.02 × 10²³) = 8.223 × 10⁻¹⁹ J
Energy = hv
where h = Planck constant = 6.626 × 10 ⁻³⁴ m²kg/s and v = frequency
c speed of light = vλ
c / λ = v
E = hc / λ
λ = hc / E = (6.626 × 10 ⁻³⁴ m²kg/s × 3.0 × 10 ⁸ m/s) / (8.223 × 10⁻¹⁹ J) = 2.41 × 10⁻⁷m = 241 nm
UV light wavelength is between 400 nm - 10 nm
