An isotope has 21 neutrons and a mass number of 40, it has 19 electrons and protons and 21 neutrons. true or false plz explain the answer

1.milk of magnesia, a suspension of mg(oh)2in water, reacts with stomach acid (hcl) in a neutralization reaction. mg(oh)2(s) + 2 hcl(aq) −→ 2 h2o(l) + mgcl2(aq) what mass of mgcl2 will be produced if 5.49 g of mg(oh)2 reacts? answer in units of g. 2.what mass of hcl is required to completely react with 5.49 g of mg(oh)2? answer in units of g.

How would you reduce the volume of gas

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)