Chemistry, 28.05.2021 06:00 Sourcandy

Help plz!
Objects that are very dense, such as iron, can decrease their density by spreading their mass out over
A. a larger mass
B. a larger volume
C. a larger density
D. a larger object

Answers: 1

Show answers

Answers

Answer from: alyssa337

hi! I hope your having a awesome day

Explanation:

Answer from: Quest

Answerd. may include all of these are many definitions of bases: the brønsted-lowry definition of acids and bases says that bases are proton acceptors.the arrhenius definition of acids and bases says that bases increase [oh⁻] in solution (thereby producing oh⁻ ions)the lewis definition of acids and bases says that bases donate electron pairs.therefore, the sensible answer is that a base may include all of the described characteristics.

Answer from: Quest

the missing options are :

(1) lower boiling point and a lower freezing point(2) lower boiling point and a higher freezing point(3) higher boiling point and a lower freezing point(4) higher boiling point and a higher freezing point

answer : the correct answer is option (3) higher boiling point and a lower freezing point

explanation :

when a non volatile solute is added to a solvent like water, it results in elevation of boiling point.

let us find the increase in boiling point of water when cacl₂ is added to water to make a solution of 1 m

step 1 : find molality of the solution

let us assume we have 1 l of solution.

$m = \frac{moles (solute)}{l ( solution)}$

$1 m = \frac{moles (cacl_{2})}{1 l }= 1 mol cacl_{2}$

let us convert this to grams of cacl₂.

molar mass of cacl2 is 111 g/mol

grams of cacl₂ = $1 mol \times \frac{111g}{mol} = 111 g cacl_{2}$

mass of solute = 111 g

assuming density of solution same as water which is 1g/ml we have ,

mass of solution = density * volume

mass of solution = $\frac{1g}{ml} \times 1000 ml = 1000 g$

mass of solution = mass of solvent + mass of solute

mass of solute = 1000g - 111g

mass of solute 889 g = 0.889 kg

the molality of the solution can be calculated as

$molality = \frac{mol (solute)}{kg ( solvent)}$

$molality = \frac{1mol}{0.889kg}$

molality = 1.12 m

step 2 : find boiling point elevation.

the elevation in boiling point is calculated as

$\bigtriangleup t_{b} = i \times k_{b} \times m$

here δtb = boiling point elevation

i = vant hoff factor which is the number of ions formed by the solute .

cacl₂ dissociates as $cacl_{2} \rightarrow ca^{2+} + 2 cl^{-}$

it forms 3 ions . therefore,

i = 3

m = molality which is 1.12 m

kb is constant for a given solvent. for water it is 0.512

$\bigtriangleup t_{b} = 3 \times 0.512 \times 1.12$

$\bigtriangleup t_{b} = 1.7$

the boiling point of water increases by 1.7 °c

step 3: find freezing point depression.

when a non volatile solute is added to water, it results in decrease in freezing point.

the formula to find freezing point depression is

$\bigtriangleup t_{f} = i \times k_{f} \times m$

kf is constant for water and its value is 1.86

$\bigtriangleup t_{f} = 3 \times 1.86 \times 1.12$

$\bigtriangleup t_{f} = 6.2$

the freezing point of water decreases by 6.2 °c

therefore we can say that, the solution will have a higher boiling point and a lower freezing point

Another question on Chemistry

Chemistry, 22.06.2019 03:10

Agas diffuses 1/7 times faster than hydrogen gas (h2). what is the molar mass of the gas? 100.10 g/mol 98.78 g/mol 86.68 g/mol 79.98 g/mol

Answers: 3

Answer

Chemistry, 22.06.2019 05:40

Calculate: select the worksheet tab. this tab you calculate the analyte concentration.  fill in the first set of boxes ("moles h2so4" and "moles naoh") based on the coefficients in the balanced equation. (if there is no coefficient, the value is 1.)  record the appropriate volumes in the "ml naoh" and "ml h2so4" boxes.  record the concentration of the titrant in the m naoh box. click calculate. what is the concentration listed

Answers: 2

Answer

Chemistry, 22.06.2019 12:00

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?

Answers: 1

Answer

Chemistry, 23.06.2019 07:20

F1.5 mol of nabh4 react, how many moles of b2h6 are formed? 2 nabh4(aq) + h2so4(aq) → 2 h2(g) + na2so4(aq) + b2h6(g)

Answers: 1

Answer

You know the right answer?

Help plz!
Objects that are very dense, such as iron, can decrease their density by spreading...