The offspring of sexual reproduction typically ----.

Bill, a lab technician, was asked to measure out sodium hydroxide (NaOH) for an experiment in a research lab. He was given a cho

Aleks04 [339]

Answer:

He is wrong . Most accurate is Buret .

Explanation:

The number of significant figure denotes the level of accuracy of a measurement .

Beaker can measure liquid in mL upto significant figure of 2 . That means it can measure volume in terms of 10 , 20 , 30mL etc . It can not measure 25 mL

accurately . The last figure of 28 mL is read by guess in the question . So it is not an accurate measurement .

Similarly , graduated cylinder can measure liquid upto significant figure of 3 . That means it can measure volume in terms of 11 , 22 , 33 mL etc . It can not measure 25.5 mL accurately . The last figure of 28.3 mL is read by guess in the question . So it is less accurate measurement .

Similarly , buret can measure liquid upto significant figure of 4 . That means it can measure volume in terms of 11.2 , 22.3 , 33.5 mL etc . It can not measure 25.53 mL accurately . The last figure of 28.32 mL is read by guess in the question . So it is most accurate among all the three instrument because it can measure accurately mL upto one tenth of it .

7 0

3 years ago

Brainliest for correct answer please show all work

Korvikt [17]

Answer:

1) Na₃PO₄ + 3 KOH ➙ 3 NaOH + K₃PO₄

2) MgF₂ + Li₂CO₃➙ MgCO₃ + 2 LiF

3) P₄ + 3 O₂➙ 2 P₂O₃

Explanation:

To balance an equation, ensure that the number of atoms of each element is equal on both sides.

Reactants would be those on the left of the arrow while products are on the right of the arrow.

Balance O and H atoms last.

Question 1:

__Na₃PO₄ + __KOH ➙ __NaOH + __K₃PO₄

Reactants: 3Na, 1P, 1K, 5O, 1H

Products: 1Na, 1P, 3K, 5O, 1H

Balance the number of Na:

__Na₃PO₄ + __KOH ➙ 3 NaOH + __K₃PO₄

Reactants: 3Na, 1P, 1K, 5O, 1H

Products: 3Na, 1P, 3K, 7O, 3H

Balance the number of K:

__Na₃PO₄ + 3 KOH ➙ 3 NaOH + __K₃PO₄

Reactants: 3Na, 1P, 3K, 7O, 3H

Products: 3Na, 1P, 3K, 7O, 3H

The equation is now balanced.

Question 2:

__MgF₂ + __Li₂CO₃➙ __MgCO₃ + __LiF

Reactants: 1Mg, 2F, 2Li, 1C, 3O

Products: 1Mg, 1F, 1Li, 1C, 3O

Balance number of Li and F atoms:

__MgF₂ + __Li₂CO₃➙ __MgCO₃ + 2 LiF

Reactants: 1Mg, 2F, 2Li, 1C, 3O

Products: 1Mg, 2F, 2Li, 1C, 3O

The equation is now balanced.

Question 3:

__P₄ + __O₂➙ __P₂O₃

Reactants: 4P, 2O

Products: 2P, 3O

Balance the number of P atoms:

__P₄ + __O₂➙ 2 P₂O₃

Reactants: 4P, 2O

Products: 4P, 6O

Balance the number of O atoms:

__P₄ + 3 O₂➙ 2 P₂O₃

Reactants: 4P, 6O

Products: 4P, 6O

The equation is now balanced.

4 0

3 years ago

The enthalpy of vaporization (ΔH°vap) of benzene is 30.7 kJ/mol at its normal boiling point of 353.3 K. What is ΔS°vap at this t

vazorg [7]

Answer: The correct answer is Option c.

Explanation:

Vaporization is defined as the physical process in which liquid particles get converted to gaseous particles.

$Liquid\rightleftharpoons Gas$

The value of standard Gibbs free energy is 0 for equilibrium reactions.

To calculate $\Delta S^o_{vap}$ for the reaction, we use the equation:

$\Delta S^o_{vap}=\frac{\Delta H^o_{vap}}{T}$

where,

$\Delta S^o_{vap}$ = standard entropy change of vaporization

$\Delta H^o_{vap}$ = standard enthalpy change of vaporization = 30.7 kJ/mol = 30700 J/mol (Conversion factor: 1 kJ = 1000 J)

T = temperature of the reaction = 353.3 K

Putting values in above equation, we get:

$\Delta S^o_{vap}=\frac{30700J/mol}{353.3K}=86.9J/(mol.K)$

Hence, the correct answer is Option c.

8 0

3 years ago

Sodium carbonate can be made by heating sodium bicarbonate: 2NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g) Given that ΔH° = 128.9 kJ/m

Ad libitum [116K]

Answer:

[tex]128^{o}C[/tex]minimum temperature will the reaction become spontaneous.

Explanation:

$\Delta G=\Delta H-T \Delta S$

From the given,

$\Delta G^{o}=33.1$

$\Delta H^{o}=128.9kJ/mol$

$Temperature\,change=25+273=98K$

$33.1=128.9-298 \Delta S$

$\Delta S=0.322kJ/mol.K$

$\Delta G=\Delta H-T \Delta S$

$0=128.9-T(0.322)=401K=218^{o}C$

Therefore, $128^{o}C$ minimum temperature will the reaction become spontaneous.

7 0

3 years ago

Help, Science test! Im stuck on this one

mote1985 [20]

Answer:

group d

Explanation: because it goes back the most amount of years

4 0

3 years ago