Magnesium and nitrogen react to form magnesium nitrate. Which of the following expressions represents this chemical reaction?

Predict the products when aqueous solutions of sodium carbonate and calcium chloride are combined.

ikadub [295]

ANSWERRRR ISSSS ▼・ᴥ・▼CCCCCC!

6 0

2 years ago

Cyclohexane has a freezing point of 6.50 ∘C and a Kf of 20.0 ∘C/m. What is the freezing point of a solution made by dissolving 0

Elza [17]

Answer: $2.49^0C$

Explanation:

Depression in freezing point is:

$T_f^0-T_f=i\times k_f\times \frac{w_2\times 1000}{M_2\times w_1}$

where,

$T_f$ = freezing point of solution = ?

$T^o_f$ = freezing point of solvent (cyclohexane) = $6.50^oC$

$k_f$ = freezing point constant of solvent (cyclohexane) = $20.0^oC/m$

m = molality

i = Van't Hoff factor = 1 (for non-electrolyte)

$w_2$ = mass of solute (biphenyl) = 0.771 g

$w_1$ = mass of solvent (cyclohexane) = 25.0 g

$M_2$ = molar mass of solute (biphenyl) =

Now put all the given values in the above formula, we get:

$(6.50-T_f)^oC=1\times (20.0^oC/m)\times \frac{(0.771g)\times 1000}{154\times (25.0g)}$

$(6.50-T_f)^oC=4.01$

$T_f=2.49^0C$

Therefore, the freezing point of a solution made by dissolving 0.771 g of biphenyl in 25.0 g of cyclohexane is $2.49^0C$

4 0

3 years ago

Which of the following compounds has a lower boiling point?<br> Li2O<br> H₂O<br> KCI<br> MgCl2

Kamila [148]

Pretty sure it’s H2O

6 0

2 years ago

The lewis representation above depicts a reaction between hydrogen (blue) and a main-group element from group (red). in this rep

Fed [463]

The question is incomplete, the complete question is;

The Lewis representation above depicts a reaction between hydrogen (blue) and a main-group element from group______ (red).

In this representation, each Y atom needs ______ electron(s) to complete its octet, and gains these electrons by forming______ bond(s) with atoms of H .

There are ______ unshared electron pair(s) and _______bonding electron pair(s) in the product molecule.

The bonds in the product are _________ (Ionic or Covalent)

Answer:

1) 16

2) 2 electrons

3) 2 bonds

4) 2 unshared pairs of electrons

5) 2 bonding pairs of electrons

6) The bonds in the product are covalent

Explanation:

Group sixteen elements have six electrons on their outermost shell. These include two unshared pairs of electrons and two unpaired electrons. These two unpaired electrons can now be covalently bonded to two hydrogen atoms to give H2Y. The compound H2Y has two lone pairs and two bond pairs of electrons.

H2Y can be a general formula for all hydrides of group 16. They are all very similar in structure but gradually differ in physical and chemical properties according to the graduated variation observed down the group.

6 0

3 years ago

Gas is heated from 480. K to 750. K and the pressure is kept constant, what final volume would result if the original volume was

attashe74 [19]

Charles law gives the relationship between volume and temperature of gas.
It states that at constant pressure volume is directly proportional to temperature
Therefore
V/ T = k
Where V - volume T - temperature in kelvin and k - constant
V1/T1 = V2/T2
Parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
Substituting the values in the equation
267 L/ 480 K = V / 750 K
V = 417 L
Final volume is 417 L

8 0

2 years ago