Hydrochloric acid reacts with metals to produce hydrogen gas according to the equation shown below. How many grams of a metal (X) will be
consumed in a reaction if 49.0 mL of 3.0 M HCl are used? The molar mass
of the metal (X) is 72.55 g/mol. Report your answer to the nearest tenth.
2 HCl + X --> XCl2 + H2

5.33g of X will be consumed

Explanation:

Based on the reaction, 2 moles of HCl reacts per mole of the metal. To solve this question we must find, as first, the moles of HCl that reacted. With these moles and the chemical equation we can find the moles of X and its mass (With molar mass) as follows:

Moles HCl:

49.0mL = 0.0490L * (3.0mol / L) = 0.147 moles HCl

Moles X:

0.147 moles HCl * (1mol X / 2mol HCl) = 0.0735 moles X

Mass X:

0.0735 moles X * (72.55g / mol) =

answer; talc and gypsum;

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.