3. After 7.9 grams of sodium are dropped into a bathtub full of water, how many grams of hydrogen gas are released? 4. Excess oxygen gas is added to 34.5 grams of aluminum and heated under pressure. How many grams of aluminum oxide are produced?

Please explain as well if possible!

Solution given:

3.

2Na=2*23g.

2O=18g.

=62g

=2 g

we have

2*23g of Na produce 2g of

Now

7.9 g of Na produce 2*7.9/(2*23)

=0.34g of

4.

we have

=3*16g*2g

4Al=4*27g

= 2*27*2g+2*16*3g

4*27g of Al produces 204g of

34.5g of Al produces 204g*34.5/(4*27)

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

lol for the pointsss