HNO2 is the formula for Nitrous Acid
I would say it is answer choice C, Laws are based on proven hypothesis by many different scientists.
Answer:
The number of formula units in 3.81 g of potassium chloride (KCl) is approximately 3.08 × 10²²
Explanation:
The given parameters is as follows;
The mass of potassium chloride produced in the chemical reaction (KCl) = 3.81 g
The required information = The number of formula units of potassium chloride (KCl)
The Molar Mass of KCl = 74.5513 g/mol
Therefore, we have;
1 mole of a substance, contains Avogadro's number (6.022 × 10²³) of formula units
Therefore;
0.051106 moles of KCl contains 0.051106 × 6.022 × 10²³ ≈ 3.077588 × 10²² formula units
From which we have, the number of formula units in 3.81 g of potassium chloride (KCl) ≈ 3.08 × 10²² formula units.
*** 2 ***
<span>if we assume volume NaCl + volume H2O = volume H2O.. i.e.. NaCl does not effect volume </span>
<span>therefore.. the units of.. </span>
<span>.. M = moles NaCl / L solution ≈ moles NaCl / L H2O </span>
<span>.. density = grams NaCl / L solution ≈ grams NaCl / L H2O </span>
<span>again.. that is our assumption </span>
<span>so we can readily see that </span>
<span>.. M = (1 mol NaCl / ___g NaCl) x (__g NaCl / L H2O) + 0 </span>
<span>ie.. </span>
<span>.. M = (1 mol NaCl / 58.5g NaCl) x density solution + 0 </span>
<span>so.. we would expect.. </span>
<span>.. m = 0.01709 mol / g </span>
<span>.. b = 0 </span>
Answer:
33.33% = 33%
Explanation:
MgCO3(s) + 2HCl (aq) --> MgCl2(aq) + H20(l) + CO2(g)
1 mole of MCO3 will produce → 1 mole of CO2
We need to get the number of mole of CO2:
and when we have 0.22 g of CO2, so number of mole = mass / molar mass
Moles = 0.22 g / 44 g/mol = 0.005 mole
Moles of Mg = moles of CO2 = 0.005 mole
Mass of Mg = moles * molar mass
= 0.005 * 84 /mol = 0.42 g
Percent of MgCO3 by mass of Mg = 0.42 g / 1.26 * 100
=33.33 %
