Molar mass NaOH =23+16+1=40 g/mol
<span> 0.100 M= 0.100 mol/L
</span>500 ml=0.500 L
0.500L*0.100 mol/L=0.0500 mol NaOH we need to prepare 500 ml solution
0.0500 mol NaOH*40g/1mol=2 g NaOH we need to prepare 500 ml solution
we need 2 g NaOH, dissolve it in small amount of water, and dilute it with water up to 500 mL
The answer is 9. Calcium nitrate is made up
of 3 different elements that equal 9 atoms.
Answer: 0.0014 atm
Explanation:
Given that,
Original pressure of air (P1) = 1.08 atm
Original volume of air (T1) = 145mL
[Convert 145mL to liters
If 1000mL = 1l
145mL = 145/1000 = 0.145L]
New volume of air (V2) = 111L
New pressure of air (P2) = ?
Since pressure and volume are given while temperature is held constant, apply the formula for Boyle's law
P1V1 = P2V2
1.08 atm x 0.145L = P2 x 111L
0.1566 atm•L = 111L•P2
Divide both sides by 111L
0.1566 atm•L/111L = 111L•P2/111L
0.0014 atm = P2
Thus, the new pressure of air when the volume is decreased to 111 L is 0.0014 atm
Answer:
(A) 2.7*10^-8, (B)3.56*10^2, (C)4.78*10^4 (D) 9.6*10^-2
Explanation:
Scientific notation is a system that allows you to express very large or very small numbers by multiplying them by multiples of 10 with positive or negative exponents
<span>9.40x10^19 molecules.
The balanced equation for ammonia is:
N2 + 3H2 ==> 2NH3
So for every 3 moles of hydrogen gas, 2 moles of ammonia is produced. So let's calculate the molar mass of hydrogen and ammonia, starting with the respective atomic weights:
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Molar mass H2 = 2 * 1.00794 = 2.01588 g/mol
Molar mass NH3 = 14.0067 + 3 * 1.00794 = 17.03052 g/mol
Moles H2 = 4.72 x 10^-4 g / 2.01588 g/mol = 2.34140921086573x10^-4 mol
Moles NH3 = 2.34140921086573x10^-4 mol * (2/3) = 1.56094x10^-4 mol
Now to convert from moles to molecules, just multiply by Avogadro's number:
1.56094x10^-4 * 6.0221409x10^23 = 9.400197448261x10^19
Rounding to 3 significant figures gives 9.40x10^19 molecules.</span>
