Hey there!
Al + HCl → H₂ + AlCl₃
Balance Cl.
1 on the left, 3 on the right. Add a coefficient of 3 in front of HCl.
Al + 3HCl → H₂ + AlCl₃
Balance H.
3 on the left, 2 on the right. We have to start by multiplying everything else by 2.
2Al + 3HCl → 2H₂ + 2AlCl₃
Now we have 2 on the right and 4 on the left. Change the coefficient in front of HCl from 3 to 4.
2Al + 4HCl → 2H₂ + 2AlCl₃
Now, for Cl, we have 4 on the left and 6 on the right. Change the coefficient in front of HCl again from 4 to 6.
2Al + 6HCl → 2H₂ + 2AlCl₃
Now, our H is unbalanced again. 6 on the left, 4 on the right. Change the coefficient in front of H₂ from 2 to 3.
2Al + 6HCl → 3H₂ + 2AlCl₃
Balance Al.
2 on the left, 2 on the right. Already balanced.
Here is our final balanced equation:
2Al + 6HCl → 3H₂ + 2AlCl₃
Hope this helps!
Answer:
5.56 × 10^23 molecules
Explanation:
The number of molecules in a molecule can be calculated by multiplying the number of moles in that molecule by Avagadro's number (6.02 × 10^23)
Using mole = mass/molar mass
Molar mass of N2O4 = 14(2) + 16(4)
= 28 + 64
= 92g/mol
mole = 85.0/92
= 0.9239
= 0.924mol
number of molecules of N2O4 (nA) = 0.924 × 6.02 × 10^23
= 5.56 × 10^23 molecules
Answer : The final temperature of the metal block is, 
Explanation :

As we know that,

.................(1)
where,
q = heat absorbed or released
= mass of aluminum = 55 g
= mass of water = 0.48 g
= final temperature = ?
= temperature of aluminum = 
= temperature of water = 
= specific heat of aluminum = 
= specific heat of water= 
Now put all the given values in equation (1), we get
![55g\times 0.900J/g^oC\times (T_{final}-25)^oC=-[0.48g\times 4.184J/g^oC\times (T_{final}-25)^oC]](https://tex.z-dn.net/?f=55g%5Ctimes%200.900J%2Fg%5EoC%5Ctimes%20%28T_%7Bfinal%7D-25%29%5EoC%3D-%5B0.48g%5Ctimes%204.184J%2Fg%5EoC%5Ctimes%20%28T_%7Bfinal%7D-25%29%5EoC%5D)

Thus, the final temperature of the metal block is, 
Answer:
B) The molecules were closer together when the juice pop was frozen.
Answer:
The answer is
<h2>1.45 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass of material = 5.01 g
volume = 3.46 mL
The density of the material is

We have the final answer as
<h3>1.45 g/mL</h3>
Hope this helps you