Alkaline earth metals
group 2 (IIA)
independent variable: how much bread there is
dependant variable: temperature, location, time, size.
hypothesis, the one with the bread will be way more moist than the one without.
control group: no bread at all.
experimental group: brownies with bread
constants: same tupperware, placement, time, size.
Answer:
1450 W
Explanation:
<u>5800n x 20m</u> =1450w
80s
Answer: 20L of H2O
Explanation:
C3H8 + 5O2 → 3CO2 + 4H2O
Recall 1mole of a gas contains 22.4L at stp
5moles of O2 contains = 5 x 22.4 = 112L
4moles of H2O contains = 4 x 22.4 = 89.6L
From the equation,
112L of O2 produced 89.6L H2O
There for 25L of O2 will produce XL of H2O i.e
XL of H2O = (25 x 89.6)/112 = 20L
Answer:
1.9 × 10² g NaN₃
1.5 g/L
Explanation:
Step 1: Write the balanced decomposition equation
2 NaN₃(s) ⇒ 2 Na(s) + 3 N₂(g)
Step 2: Calculate the moles of N₂ formed
N₂ occupies a 80.0 L bag at 1.3 atm and 27 °C (300 K). We will calculate the moles of N₂ using the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 1.3 atm × 80.0 L / (0.0821 atm.L/mol.K) × 300 K = 4.2 mol
We can also calculate the mass of nitrogen using the molar mass (M) 28.01 g/mol.
4.2 mol × 28.01 g/mol = 1.2 × 10² g
Step 3: Calculate the mass of NaN₃ needed to form 1.2 × 10² g of N₂
The mass ratio of NaN₃ to N₂ is 130.02:84.03.
1.2 × 10² g N₂ × 130.02 g NaN₃/84.03 g N₂ = 1.9 × 10² g NaN₃
Step 4: Calculate the density of N₂
We will use the following expression.
ρ = P × M / R × T
ρ = 1.3 atm × 28.01 g/mol / (0.0821 atm.L/mol.K) × 300 K = 1.5 g/L
