Water (2850 g ) is heated until it just begins to boil. if the water absorbs 5.53×105 j of heat in the process, what was the initial temperature of the water?

Answer is 54 °C.

Explanation;

We can simply use heat equation

Q = mcΔT  

 Where Q is the amount of energy transferred (J), m is the mass of the substance (kg), c is the specific heat (J g⁻¹ °C⁻¹) and ΔT is the temperature difference (°C).

Let's assume that the initial temperature is T.

Q = 5.53 × 10⁵ J

m = 2850 g

c = 4.186 J/g °C

ΔT = (100 - T)  °C     Since the water is boiling, the final temperature is 100 °C.

By applying the equation,

5.53 × 10⁵ J  = 2850 g  x 4.186 J/g °C  x (100 - T)  °C

(100 - T)  °C = 5.53 × 10⁵ J  / (2850 g  x 4.186 J/g °C  )

(100 - T)  °C = 46.35 °C

         T        = 100 - 46.35 C = 53.65 °C

                   ≈ 54 °C

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.