There are 3 significant figures. Significant numbers are the numbers that build up your total number. 1-9 always count, 0 only counts if it’s after another number. For example: 0,901 has 3 significant numbers as does 0,910. 9,10 also has 3. 0,09 has just 1.
Answer:
Mass= 2.77g
Explanation:
Applying
P=2.09atm, V= 1.13L, R= 0.082, T= 291K, Mm of N2= 28
PV=nRT
NB
Moles(n) = m/M
PV=m/M×RT
m= PVM/RT
Substitute and Simplify
m= (2.09×1.13×28)/(0.082×291)
m= 2.77g
There are about 118 elements on the periodic table. <span />
Answer:
P= 7.01 atm
P(CO₂)= 2.34 atm
Explanation:
Step 1: Convert the temperature to Kelvin
We will use the following expression.
K = °C + 273.15
K = 32.0°C + 273.15 = 305.2 K
Step 2: Calculate the total number of moles of the mixture
We will use the following expression.
n = nCO₂ + nN₂ = 2.33 mol + 4.66 mol = 6.99 mol
Step 3: Calculate the total pressure of the mixture
We will use the ideal gas equation.
P × V = n × R × T
P = n × R × T / V
P = 6.99 mol × 0.0821 atm.L/mol.K × 305.2 K / 25.0 L
P= 7.01 atm
Step 4: Calculate the partial pressure of carbon dioxide
We will use the ideal gas equation.
P(CO₂) × V = nCO₂ × R × T
P(CO₂) = nCO₂ × R × T / V
P(CO₂) = 2.33 mol × 0.0821 atm.L/mol.K × 305.2 K / 25.0 L
P(CO₂)= 2.34 atm
Answer:
Molarity is a unit that measures how much moles of solute dissolved in a liter of solvent. Molarity expressed using capital M while molarity, a different unit, expressed using lower case m.
We want to make 0.005 M solution which means we need 0.005 moles of KmnO4 per liter of water. First, we have to calculate how many grams of KMnO4 we need for the solution.
We want to make 250ml solution, so the number of moles of KMnO4 we need will be: 0.005 mol/liter *(250 ml * 1liter/1000ml)= 0.005 mol/liter * 1/4 liter = 0.00125 moles
The molecular mass of KMnO4 is 158g/mol, so the mass of KMnO4 we need will be: 0.00125 moles * 158g/mol= 0.1975 grams
We know that we need 0.1975 g of KMnO4, now we weigh them and put it inside a dish. After that, we prepare Erlenmeyer or a volumetric flask filled with water half of the volume needed(125ml). Pour the weighted solute into the flask, stir until all solute dissolved.
Then we add water to the container slowly until its volume reaches the 250ml mark.