Answer:
1.52 g NaOH
Explanation:
The molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance.
Molar mass of NaOH is 40.0 g/mol
40.0 g/mol contains 6.022 × 10²³ molecules
∴ 2.30 × 10²² molecules will contain (2.30 × 10²²) * (40.0)/6.022× 10²³
= 1.52 g NaOH
Answer: 8.59 L of oxygen gas are needed to produce 100 kJ of energy at STP
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.
Standard condition of temperature (STP) is 273 K and atmospheric pressure is 1 atmosphere respectively.
1 mole of every gas occupy volume at STP = 22.4 L
The balanced chemical reaction is:
3909.9 kJ of of energy is produced by =
100 kJ of oxygen gas are needed to produce =
corrected question:
Determining Density and Using Density to Determine Volume or Mass
(a) Calculate the density of mercury if 1.00 × 10 g occupies a volume of 7.36 cm³
(b) Calculate the volume of 65.0 g of liquid methanol (wood alcohol) if its density is 0.791 g/mL.
(c) What is the mass in grams of a cube of gold (density = 19.32 g/cm) if the length of the cube is 2.00 cm?
(d) Calculate the density of a 374.5-g sample of copper if it has a volume of 41.8 cm³ A student needs 15.0 g of ethanol for an experiment. If the density of ethanol is 0.789 g/mL, how many milliliters of ethanol are needed? What is the mass, in grams, of 25.0 mL of mercury (density = 13.6 g/mL)?
Answer:
density =
ρ=m/v ,m=ρv, v=m/ρ
(a)m=1*10g , v=7.36cm³
ρ=10/7.36 =1.36g/cm³
(b) m=65g, ρ=0.791 g/mL.
v= 65/0.791 =82.17g/mL
(c) ρ=19.32g/cm³, l=2cm, v=l³=8cm³
m=19..32*8=154.56g/cm³
(d) mass of copper=374.5g , v=41.8cm³
ρ=374.5/41.8 =8.96g/cm³
mass of ethanol=15g, density of ethanol=0.789g/mL
v=15/0.789 =19.01mL
volume of mecury=25mL, density of mercury=13.6g/mL
m=25*13.6=340g
Answer:
0.4M NaOH
Explanation:
Molarity, M, is an unit of concentration widely used defined as the ratio between moles of solute (In this case, NaOH) and volume of solution in liters.
As the solution contains 2 moles of NaOH-Moles of solute- in 5L of solution, the molarity is:
2 moles NaOH / 5L =
<h3>0.4M NaOH</h3>
Alpha particles because two protons and two neutrons