Chemistry Sig Digs Problem: Finding Thickness of Metal Sheet - Homework Solution

[Nellen2222]

Homework Statement

A sheeet of metal is 19.3mm wide and 48.2.mm long. if it weighs 8.171g and the density of the metal is 6.69g/cm63, what is the thickness in mm?

Homework Equations

V= L*W*H
H=V/L*W
D=M/V
V=M/D

The Attempt at a Solution

8.161g(4sig)/6.69g/cm^3(density, so sig digs not counted, right?)

= 1.22137cm^3(4sig) : convert into mm: 1221.37mm(4sig)

Area given: 19.3*48.2=930.26

1221.375(4sig) / 930.26(3sig)

= 1.31(sig) (thickness)

Value comes out properly if multiply all 3 volumes. Did I do the sig-digs correctly? Thanks.

 

[nate808]

Hello,

Your solution looks good. Here are the steps I took to verify:

1. Convert the dimensions from mm to cm to match the density unit:

19.3mm = 1.93cm (2 sig figs)
48.2mm = 4.82cm (3 sig figs)

2. Calculate the volume using the given formula:

V = L*W*H = 1.93cm * 4.82cm * H = 9.2974cm^3

3. Calculate the thickness using the given formula:

H = V / (L*W) = 9.2974cm^3 / (1.93cm * 4.82cm) = 0.95cm (2 sig figs)

4. Convert the thickness back to mm:

0.95cm = 9.5mm (2 sig figs)

So, the thickness in mm is 9.5mm (2 sig figs). Your calculation is correct and your use of significant figures is appropriate. Great job!