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2 years ago

20 POINTS I will give brainliest to whoever answers correctly

Chemistry

1 answer:

Romashka [77]2 years ago

6 0

All organisms need four types of organic molecules: nucleic acids, proteins, carbohydrates and lipids; life cannot exist if any of these molecules are missing.

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What happens in a neutralization reaction?

mina [271]

Answer:

Answer is letter B

Explanation:

The first one is wrong because acids release H+, not bases.

The third one is wrong because the pH is exactly 7, not greater.

The last one is wrong because it is vague and does not fit a neutralization reaction.

7 0

2 years ago

The energy of a pendulum is recorded at different positions in the table below. Use the data in the table to determine the amoun

natta225 [31]

Answer:

36.55 J

Explanation:

PE = Potential energy

KE = Kinetic energy

TE = Total energy

The following data were obtained from the question:

Position >> PE >>>>> KE >>>>>> TE

1 >>>>>>>> 72.26 >> 27.74 >>>> 100

2 >>>>>>>> 63.45 >> x >>>>>>>> 100

3 >>>>>>>> 58.09 >> 41.91 >>>>> 100

The kinetic energy of the pendulum at position 2 can be obtained as follow:

From the table above, at position 2,

Potential energy (PE) = 63.45 J

Kinetic energy (KE) = unknown = x

Total energy (TE) = 100 J

TE = PE + KE

100 = 63.45 + x

Collect like terms

100 – 63.45 = x

x = 36.55 J

Thus, the kinetic energy of the pendulum at position 2 is 36.55 J.

7 0

2 years ago

A solution was made by dissolving 5.10 mg of hemoglobin in water to give a final volume of 1.00 ml. the osmotic pressure of this

Assoli18 [71]

The molecular weight of hemoglobin can be calculated using osmotic pressure

Osmotic pressure is a colligative property and it depends on molarity as

πV = nRT

where

π = osmotic pressure

V = volume = 1mL = 0.001 L

n = moles

R = gas constant = 0.0821 L atm / mol K

T = temperature = 25°C = 25 + 273 K = 298 K

Putting values we will get value of moles

$moles=\frac{\pi V}{RT}=\frac{0.00195X0.001}{0.0821X298}mol$

we know that

$moles=\frac{mass}{molarmass}$

Therefore

$molarmass=\frac{mass}{moles}=\frac{5.10X10^{-3}g}{7.97X10^{-8}}=6.399X10^{4}g$

5 0

2 years ago

Part 1: Name the type of chemical reaction that occurs when calcium hydroxide (Ca(OH)2) reacts with nitric acid (HNO3).

liberstina [14]

Answer:

For 1: Neutralization reaction

For 2: Zinc is more reactive than lead and less reactive than calcium.

Explanation:

For (1):

When a base reacts with an acid to form a salt and water molecule, it is known as a neutralization reaction. The general equation follows:

$HX+BOH\rightarrow BX+H_2O$

The chemical equation for the reaction of calcium hydroxide and nitric acid follows:

$Ca(OH)_2(aq)+2HNO_3(aq)\rightarrow Ca(NO_3)_2(aq)+2H_2O(l)$

For (2):

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its salt solution. The general chemical equation follows:

$A+BX\rightarrow AX+B$

where,

Metal A is more reactive than metal B

The reactivity of metals is judged by the reactivity series where a metal lying above in the series is more reactive than the metal lying below it.

From the reactivity series below,

Zinc lies above in the series than lead thus is more reactive and will easily replace lead from its aqueous solution.

While zinc lies below in the series than calcium thus is less reactive and will not easily replace calcium from its aqueous solution.

$Zn(s)+Pb(NO_3)_2(aq)\rightarrow Zn(NO_3)_2(aq)+Pb(s)$

$Zn(s)+CaCl_2(aq)\rightarrow \text{No reaction}$

5 0

3 years ago

Boiling occurs when molecules being changed from liquid to gas plz tell me the answer true or false

Valentin [98]

Answer:

Liquid to Gas

Explanation:

The particles need energy to rise and over come the attractions between them as the liquid gets warmer more particles have sufficient, energy to escape from liquid. eventually even particles in the middle of the liquid form bubbles of gas in the liquid At this point the liquid is boiliing and turning into gas.

5 0

2 years ago