How many grams of mg are needed to react completely with 3.80 l of a 2.50 m hf solution? mg + 2hf yields mgf2 + h2 a. 4.75 g b. 9.50 g c. 115 g d. 190 g

Molarity = number of moles of solute / liters of solution
Therefore,
number of moles = molarity * volume
number of moles of HF = 2.5 * 3.8 = 9.5 moles

From the balanced equation given:
one mole of Mg is required to react with two moles of HF, therefore, to get the number of moles of Mg that reacts with 9.5 moles of HF, we will just do a cross multiplication as follows:
number of moles of Mg = (9.5*1) / 2 = 4.75 moles

From the periodic table:
molar mass of Mg = 24.305 grams

number of moles = mass / molar mass
therefore,
mass = number of moles * molar mass
mass og Mg = 4.75 * 24.305 = 115.44 grams

(c)

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later