Answer:
35.5450 will be rounded to 35.55
Explanation:
=35.5450
if the last digit is less than 5 then it will be ignored
=35.545
when the dropping digit is 5 then the retaining digit will increse by a factor of 1
=35.55
i hope this will help you
Answer:
of 
are found in 39.5 grams of .
Explanation:
Atomic weights : P= 31, F= 19,
molar mass of = 1 atomic weight of P+ 5 atomic weight of
F= 31+5 
19
= 31+95
=126 g/mole
moles in 39.5 gm of
= 
= 
=0.3134 moles
1 mole of any substance contains
0.3131 moles contains 0.3134
Therefore, of are found in 39.5 grams of .
To determine the mass of the hydrogen gas that was collected, we calculate for the moles of hydrogen gas from the conditions given. In order to do this, we need an equation which would relate pressure, volume and temperature. For simplicity, we assume the gas is an ideal gas so we use the equation PV = nRT where P is the pressure, V is the volume, n is the number of moles of the gas, T is the temperature and R is the universal gas constant. We calculate as follows:
PV = nRT
n = PV / RT
n = (18.6/760) (7.80) / 0.08205 ( 21 + 273.15)
n = 0.0079 mol
Mass = 0.0079 mol ( 18.02 g / mol ) = 0.1425 g H2
Explanation:
a) Using the provided information about the density of gold, the sample size, thickness, and the following equations and comersion factors, find the area of the gold leaf:
Gold 
First, find the volume of the sample and then find the area of the sample.
b. Using the provided information from part 
), the radius of the cylinder, and the following equation for the volume of a cylinder, find the length of the fiber :
