Which of the following represents a physical change?

CHEMISTRY · Single correct · AP · Chemistry · Chemical Reactions · Chemical Reactions

Problem

Which of the following represents a physical change? (a)

2\,\mathrm{H_2O_2(aq)} \;\rightarrow\; 2\,\mathrm{H_2O(l)} + \mathrm{O_2(g)}

(b)

\mathrm{NH_3(g)} + \mathrm{HCl(g)} \;\rightarrow\; \mathrm{NH_4Cl(s)}

(c)

\mathrm{CO_2(g)} \;\rightarrow\; \mathrm{CO_2(s)}

(d)

\mathrm{AgNO_3(aq)} + \mathrm{NaCl(aq)} \;\rightarrow\; \mathrm{AgCl(s)} + \mathrm{NaNO_3(aq)}