Answer:
D.) Science is always changing, so experiments need to be repeated
Explanation:
I’m pretty sure that they mostly design building structures!
Answer:
0.482 ×10²³ molecules
Explanation:
Given data:
Volume of gas = 2.5 L
Temperature of gas = 50°C (50+273 = 323 k)
Pressure of gas = 650 mmHg (650/760 =0.86 atm)
Molecules of N₂= ?
Solution:
PV= nRT
n = PV/RT
n = 0.86 atm × 2.5 L /0.0821 atm. mol⁻¹. k⁻¹. L × 323 k
n = 2.15 atm. L /26.52 atm. mol⁻¹.L
n = 0.08 mol
Number of moles of N₂ are 0.08 mol.
Number of molecules:
one mole = 6.022 ×10²³ molecules
0.08×6.022 ×10²³ = 0.482 ×10²³ molecules
Answer:
2nd option
Explanation:
Molarity is the number of moles of the solute (NaCl) in 1 litre of the solution (NaCl solution).
Given: concentration= 232g/ L
what we are trying to achieve is __mol/ L.
So in 1 litre, we have 232g of NaCl.
To convert mass to mole, we divide it by the Mr.
Given that the Mr is 58g/mol,
number of moles
= 232 ÷58
= 4
Thus, 1 litre has 4 moles of NaCl.
Therefore, the molarity is 4.0 mol/L.
Answer:
1 mole of carbon-12 has 6.02 x 1023 atoms. you need to know how many moles there are in 20 grams of carbon-12. One mole of anything is the same number of grams as the molecular mass, since the molecular mass of carbon-12 is 12, there are 12 grams in 1 mole of it, and therefore 20/12 = 5/3 moles in 20 grams