Answer:
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
Explanation:
Answer:
It is at the greater angle (higher solar elevation) that the surface area receives the most energy because the rays are spread out less. ... The smaller the elevation angle (30°, 20°, 10°) the less energy received per square centimeter, because the rays spread out over a greater area.
Explanation:
correct me if I'm wrong
Answer is: molar mass
of compound is 154,58 g/mol.<span>
m(</span>naphthalene<span>) = 10 g = 0,01 kg.
m(unknown compound) = 1,00 g.
</span>Δ<span>T (solution) = 4,47 °C.
Kf(</span>naphthalene) = 6,91°C/m<span>; cryoscopic
constant.
M</span>(unknown compound) = Kf(naphthalene)· m(unknown compound) ÷
m(naphthalene)<span> · ΔT(solution).
M(xylene) = </span>6,91°C/m<span> · 1 g ÷ 0,01 kg · 4,47</span>°C<span>.
M(xylene) = 154,58 g/mol.</span>
