Answer:
Molar mass of Ca = 40 g / mol , given 123 g Ca is 123/40= 3.075 moles,
1 mole = 6.022 * 10^23 atoms, so 3.075 moles Ca= 18.51*10^23 atoms
Explanation:
Cylinder D
temperature is the measurement of average kinetic energy of a sunstance. since cylinder D has the highest average velocity, it has the highest average kinetic energy among the 4 cylinders, thus cylinder D is the hottest.
Answer:
30 kJ
Explanation:
Arrhenius equation is given by:

Here, k is rate constant, A is Pre-exponential factor, Ea is activation energy and T is temperature.
taking natural log of both side
ln k = ln A - Ea/RT
In Arrhenius equation, A, R and T are constant.
Therefore,

is the lowering in activation energy by enzyme,
R = 8.314 J/mol.K
T = 37°C + 273.15 = 310 K


Answer: m= 1.02x10² g AlCl3 or 1091.3 g AlCl3
Explanation: solution attached.
Convert mass of Mg to moles
Do the mole ratio between Mg and AlCl3 based from the balanced equation.
Convert moles of AlCl3 to mass using its molar mass.