To calculate the of a moving object, divide the displacement by the time interval in which the displacement occurred.

Hello!

To calculate the speed(velocity) of a moving object, we can divide the displacement by the time interval in which the displacement occurred.

This is based off the formula:
v=d/t

Where v=velocity, d=total displacement, t=Time interval

Hope this helps. Any question please just ask. Thank you kindly.

Speed

Explanation: Scalar quantity is the quantity that only possess magnitude but no direction.

Vector quantity is the quantity that only possess magnitude as well as  direction.

Speed is defined as the displacement of an object per unit time and is a scalar quantity as it does not involve any direction.

Velocity is defined as the distance moved by an object per unit time and is a vector quantity as it deals with magnitude as well as direction.

32.3%

Explanation:

Percent yield is defined as:

Actual yield (125.5g) / Theoretical Yield * 100

To find theoretical yield we have to find the moles of aluminium. As 2 moles of Al produce 2 moles of AlCl3, the moles of Al = Moles AlCl3.

With these moles we can find the mass assuming a 100% of yield (Theoretical Yield) as follows:

Moles Al = Moles AlCl3 (Molar mass Al = 26.98g/mol)

72g Al * (1mol / 26.98g) = 2.67 moles AlCl3

Mass AlCl3 (Molar mass: 133.34g/mol)

2.67 moles AlCl3 * (133.34g / mol) = 355.8g AlCl3

Percent Yield = 125.5g / 355.8g * 100 =

32.3%