Answer:
18.4 g
Explanation:
M(He) = 4.0 g/mol
4.6 mol * 4.0 g/ 1 mol = 18.4 g
The general formula of an acid is HX where H+ acts as the cation while X can be a halogen (Cl-, Fl-, Br-, etc) and acts as the anion. There are also cases where X is an ion like SO42-, which brings two atoms of H in the formula. Strong acids dissociate completely while weak acids do not.
Answer: The coefficient we should change first is for .
Explanation:
The given reaction equation is as follows.
Here, number of atoms present on reactant side are as follows.
- Al = 1
- Ni = 1
- = 2
Number of atoms present on the product side are as follows.
- Al = 1
- Ni = 1
- = 3
To balance this equation, multiply Al by 2 and by 3 on reactant side. Also, multiply by 2 and Ni by 3 on the product side.
Hence, the equation can be rewritten as follows.
Now, number of atoms present on reactant side are as follows.
- Al = 2
- Ni = 3
- = 6
Number of atoms present on product side are as follows.
- Al = 2
- Ni = 3
- = 6
Since, the atoms on both reactant and product side are same. Hence, it is now a balanced chemical equation.
Thus, we can conclude that the coefficient we should change first is for .
Answer:
1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants
2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils
3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules
4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules
5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms
6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms
I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.
Answer:
13.28 mol.
Explanation:
- We can use the general law of ideal gas:<em> PV = nRT.</em>
where, P is the pressure of the gas in atm (P = 1.32 atm).
V is the volume of the gas in L (V = 242.0 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K).
T is the temperature of the gas in K (T = 20.0° + 273 = 293.0 K).
∴ n = PV/RT = (1.32 atm)(242.0 L)/(0.0821 L.atm/mol.K)(293.0 K) = 13.28 mol.