An endothermic process is a process that needs energy in order to proceed. This is the opposite of exothermic which is a process of releasing energy. During an endothermic process, the temperature of the system is increased thus exciting the molecules and allowing them to move faster. This will cause liquid to vaporize.
Answer:
Explanation: well I think 6.02 x 10^23 is 1 mole. So do 1/6.02 x 10^23 = x/1.3 x 10^24
Answer:
The correct answer is a
Explanation:
The formula for density is mass ÷ volume. Hence, a balance is required to determine the mass while a measuring/graduated cylinder is required to determine the volume.
The ideal measuring cylinder and balance to be used should have an uncertainty of just 0.1 ml and 0.1 g respectively. This reduces the chances of the answer gotten from the formula above to be more than 3 significant figures.
For example, if the volume to be used is 4.0 ml and the mass of this volume is 3.5 g, the density will be
Density = 3.5 ÷ 4
Density = 0.875 g/cm³ or 0.875 g/ml
NOTE that cm³ is the same measurement as mL
The answer above is in 3 significant figures
Answer:
1.)calcium+hydrochloric acid -->calcium chloride +hydrogen
2.)Ca + 2HCl -->CaCl2 + H2
3.)3.55g
Explanation:
1.) pretty self explanatory
2.)Ca + HCl -->CaCl2 + H2
then balance
Ca + 2HCl -->CaCl2 + H2 (+2 infront of Hcl)
3.) take calcium and calcium chloride
Ca + CaCl2
then you need the relative atomic mass of both
Ca=40
CaCl2=71 (40+(35.5x2))
Ca=40 40/40=1 1x2=2g
Then repeat that exact equation for calcium chloride
CaCl2=71 71/40=1.775 1.775x3=3.55g
