5 How many J of energy are needed to raise the temperature of 18.3 g of
water from 11.88°C to 49.32°C?*
2540 J
1740 J
2870 J
3570 J

Q = mcΔT, where Q is the heat energy, m is the mass, c is the specific heat, and ΔT is the change in temperature (T₂-T₁). The specific heat of water is 4.184 J/g °C. We are given the mass of water (m = 18.3 g), the final temperature (T₂ = 49.32 °C), and the initial temperature (T₁ = 11.88 °C). The change in temperature, ΔT, equals 49.32 °C - 11.88 °C = 37.44 °C. With all these values at hand, we can solve for the amount of energy needed, Q:

Q = (18.3 g)(4.184 J/g °C)(37.44 °C) = 2866.7 J ≈ 2870 J (three sig figs).

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer