Round the following to three significant figures. a 17.5555 km 16 b. 1.0007 c.23.34271d. 99.991

When 4.5 mol al react with 11.5 mol hcl, what is the limiting reactant, and how many moles of h2 can be formed?

ahrayia [7]

1°/ . 2 Al + 6 HCl → 2 AlCl3 + 3 H2

k1 = n(Al) / 2 = 4,5 / 2 = 2,25 
k2 = n(HCl) / 6 = 11,5 / 6= 1,92 

k2 < k1 ==> HCl is the limiting reactant 

6 mol of HCl ---> 2 mol of H2 
11,5 mol of HCl ---> 3,83 mol of H2

5 0

3 years ago

Someone plz help me !! Science Or Bias?

Artist 52 [7]

1st one is Science and the 2nd one is Bias

8 0

3 years ago

the most common source of copper (Cu) is the mineral chalcopyrite (CuFeS2). How many kilograms of chalcopyrite must be mined to

lara [203]

0.650 kg... I think,
But what are the answer choices?

3 0

3 years ago

What contribution did these scientists make to atomic models of the atom?

SashulF [63]

Answer:

Explanation:

Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass.

In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged. In addition, he also studied positively charged particles in neon gas.

Rutherford overturned Thomson's model in 1911 with his well-known gold foil experiment in which he demonstrated that the atom has a tiny and heavy nucleus. Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure.

The Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons. Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element.

7 0

3 years ago

What are the Lewis definitions of an acid and a base? In what way are Bronsted definitions? they more general than the In terms

kati45 [8]

Explanation:

Lewis definition of Acids and Bases

Chemical species which are capable of accepting electron pairs or donating protons are called Lewis acid.

Chemical species which are capable of donating electron pairs or accepting protons are called Lewis base.

Bronsted definition of acids and bases

Chemical species which are capable of donating H+ are called Bronsted acids.

Chemical species which are capable of accepting H+ are called Bronsted bases.

So all Bronsted acids are Lewis acids but all Lewis acids are not Bronsted acids.

For a chemical species to behave as Lewis acid, they must have:

Incomplete octet
Double bond
Vacant d-orbitals

For example, in BF3, octet of boron is incomplete, so it can accept a pair of electron and behaves as Lewis acid.

For a chemical species to behave as Lewis base, they must have:

lone pair of electrons

For example, NH3 and OH, both N and O have lone pairs of electrons, hence behave as Lewis base.

4 0

3 years ago