1) we can calculate the molecular weight of H₃PO₄
atomic mass (H)=1 amu
atomic mass (P)=31 amu
atomic mass (O)=16 amu
molecular weight (H₃PO₄)=3(1)+31+4(16)=98 amu.
1 mol (H₃PO₄)=98 g
1 mol= 6.022 * 10²³ molecules.
2) we calculate the mass of 4.00*10²³ molecules.
98 g-------------------6.022*10²³ molecules
x------------------------4.00*10²³ molecules
x=(98 g * 4.00*10²³ molecules) / 6.022*10²³ molecules≈65 g
Answer: 65 g
<span>7.15 degrees C
The specific heat capacity of water is 4.1813 J/(g*K). So we have 3 values with the units kJ, g and J/(g*K). We can trivially convert from kJ to J by multiplying by 1000. And we want to get a result with the unit K (degrees Kelvin). So let's do it. First, let's cancel out the g unit by multiplying.
4.1813 J/(g*K) * 485 g = 2027.9305 J/K
Now we can cancel out the J unit by dividing. But if we divide by the energy, we'll be left with the reciprocal of K, not K. So instead divide by the J/K unit. So
14500 J / 2027.9305 J/K = 7.150146418 K
Rounding to 3 significant figures gives us 7.15 K.
And since degrees C and degrees K are the same size, the temperature will increase by 7.15 degrees C</span>
Answer:
Explanation:
mass of one virus = 9.0 x 10⁻¹² mg
mass of one mole = 6.02 x 10²³ x mass of one virus
= 6.02 x 10²³ x 9.0 x 10⁻¹²
= 54.18 x 10¹¹ mg
= 54 x 10⁸ g .
= 54 x 10⁵ kg .
b )
let n be no of moles of virus that will be equal to weight of oil tanker
n x 54 x 10⁵ = 3 x 10⁷
n = 5.5555
rounding off to 2 significant figure
5.6 moles Ans .
Answer:
There are three rules on determining how many significant figures are in a number:
Non-zero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
Answer:
geologists
Explanation:
they use acid test in order to determine if the sample is a carbonate.
