All categories

3 years ago

PLZ HELP WITH THESE QUICK// WILL AWARD BRANLIEST

Chemistry

1 answer:

Tom [10]3 years ago

5 0

Answer 1

The sample will dissolve in more than 1 minute.

Explanation :-

Generally Solubility and rate of solubility of substances increase with the increase in temperature. So lower the temperature less fast will it dissolve in the same amount of water.

Since at 50 C it takes 1 minute to dissolve, at 20 C which is lower temperature it will take more time to dissolve.

Answer 2

Transition metals

Explanation:-

Hardness depends on the extent of metallic bonding for metals. More the number of electrons more the metallic bonding.

Alkali metals with just 1 valence electron have weak metallic bonding. Alkaline earth metals have just 2 valence electrons. Transition elements has more electrons in penultimate shell and valence shell than lanthanides. Transition metals with most metallic bonding are the hardest

You might be interested in

How and why do ionic bonds form?

babymother [125]

Ionic bonds are formed when one of the two atoms that are reacting has excess electrons and transfer the electrons to the atom that is deficient in electrons. During the formation of the ionic bond, one of the reacting atoms will donate electrons and form positive ion.

7 0

3 years ago

Predict the following product(s) of the following reaction? F2 + KCI →

slega [8]

Answer:

${ \rm{F _{2(g)} + 2KCl _{(aq)} → { \bold{2KF _{(g)} + Cl_{2(g)} }}}}$

Explanation:

» The prediction is 98% correct because single displacement reaction type is highly possible.

This is because Fluorine has is more electronegative than Chlorine in Potassium Chloride. So, it strongly displaces Chlorine from the solution hence forming Chlorine gas.

» The 2% of wrong prediction maybe because of wrong reactant measurements following mole concept chemistry.

If you are asked the observation,

Observation » A green yellowish gas is formed.

This gas is Chlorine gas (Cl2)

5 0

2 years ago

Consider the neutralization reaction 2 HNO 3 ( aq ) + Ba ( OH ) 2 ( aq ) ⟶ 2 H 2 O ( l ) + Ba ( NO 3 ) 2 ( aq ) A 0.120 L sample

k0ka [10]

Answer:

The concentration of the HNO3 solution is 0.150 M

Explanation:

Step 1: Data given

Volume of the unknown HNO3 sample = 0.120 L

Volume of the 0.200 M Ba(OH)2 = 45.1 mL

Step 2: The balanced equation

2HNO3 + Ba(OH)2 ⟶ Ba(NO3)2 + 2H2O

Step 3: Calculate moles Ba(OH)2

moles Ba(OH)2 = molarity * volume

moles Ba(OH)2 = 0.200 M * 0.0451 L

moles Ba(OH)2 = 0.00902 moles

Step 4: Calculate moles of HNO3

For 1 mole of Ba(OH)2 we need 2 moles of HNO3

For 0.00902 moles of Ba(OH)2 we need 2*0.00902 = 0.01804 moles

Step 5: Calculate molarity of HNO3

molarity = moles / volume

molarity = 0.01804 / 0.120 L

Molarity = 0.150 M HNO3

The concentration of the HNO3 solution is 0.150 M

6 0

3 years ago

What role in a factory does the cell membrane play

Vilka [71]

The plasma membrane

7 0

3 years ago

What would be the temperature of 0.6 moles of fluorine that occupy 15 L at 2,300 mmHg?

Anna [14]

Answer: The temperature of 0.6 moles of fluorine that occupy 15 L at 2,300 mmHg is 920 K

Explanation:

According to ideal gas equation:

$PV=nRT$

P = pressure of gas = 2300 mm Hg = 3.02 atm (760mmHg=1atm)

V = Volume of gas = 15 L

n = number of moles = 0.6

R = gas constant = $0.0821Latm/Kmol$

T =temperature = ?

$T=\frac{PV}{nR}$

$T=\frac{3.02atm\times 15L}{0.0821Latm/K mol\times 0.6mol}=920K$

Thus the temperature of 0.6 moles of fluorine that occupy 15 L at 2,300 mmHg is 920 K

8 0

3 years ago