The density of gold is 19.3 g/cc (g/ml). If a gold rod has a diameter of 4.20cm and 8.0 cm long. What is the mass?
I just need to know if I did this right...
r= 2.1
3.14 x 2.1^2 x 8.0 = 110.835g
19.3 g/cc x 110.835g = 2139.12 g/ml
m = 2139.12
The digits are ok.
If your prof watches significant figures, your final answer should be rounded to 2.14 x 10^3 and you omitted the units; i.e., grams.
In a car gas tank, 46.0 g of gasoline burns consuming 173 g of oxygen. The resultant products are carbon dioxide are carbon dixide and water. What is the total combined mass of the products?
Would I just add 46.0g + 173g?
I can't remember how to do it...
How do you determine the type and number of each type of element in H2SO4?
To calculate the mass of the gold rod, you need to use the formula for the volume of a cylinder, which is V = πr^2h, where r is the radius and h is the height (or length in this case) of the cylinder.
First, you correctly calculated the radius by dividing the diameter by 2:
r = 4.20 cm / 2 = 2.10 cm
Next, you used the formula V = πr^2h to find the volume:
V = π(2.10 cm)^2(8.0 cm) = 111.12 cm^3 (rounded to two decimal places)
Now, since the density of gold is given as 19.3 g/cm^3, you can use the formula density = mass/volume to solve for the mass:
mass = density x volume
mass = 19.3 g/cm^3 x 111.12 cm^3 = 2145.936 g (rounded to three decimal places)
So, the mass of the gold rod is approximately 2145.936 grams.