B
1. magnesium hydroxide + sulfuric acid sulfate +————

2. calcium hydroxide + hydrochloric acid calcium
+ water+————

3. lead hydroxide + nitric acid lead nitrate +————-

4. sodium hydroxide + sulfuric acid
+ water————-

5. potassium hydroxide + citric acid potassium
+ water————-

6. silver hydroxide + hydrochloric acid chloride +———

7. aluminium hydroxide + phosphoric acid———-

Answer:

Volume of the sulfuric acid (25cm³), same mass of each metal (1g)

Explanation:

In an experiment, the CONTROL VARIABLE also known as constant is the variable that is kept unchanged for all groups in an experiment. This is done in order not to influence the outcome of the experiment.

In this case, students are trying to investigate the reactivity of four different metals. They added 1 g of each metal to 25cm³ of sulfuric acid and recorded the temperature change. Based on the explanation of control variable above, the VOLUME OF SULFURIC ACID (25cm³) and the MASS OF EACH METAL (1g) are the CONTROL VARIABLES because they are the same or unchanged in this experiment.

Answer:

See explanation

Explanation:

The reaction between alcohol and acidified potassium dichromate  is a redox reaction. This reaction can be used to detect a drunken driver.

Alcohols can be oxidized to aldehydes, ketones and carboxylic acids depending on the structure of the alcohol. Primary alcohols yield adehydes and carboxylic acids while secondary alcohols are oxidized to ketones.

The colour of the acidified potassium dichromate turns from orange to green when exposed to alcohols from the breath of a drunken driver.

Answer:

The density (more precisely, the volumetric mass density; also known as specific mass), of a substance is its mass per unit volume. The symbol most often used for density is ρ (the lower case Greek letter rho), although the Latin letter D can also be used.

Answer:

[tex]1.167\times 10^{-3}\ \text{mol/h}[/tex]

Explanation:

[tex]R_1[/tex] = Rate of diffusion of [tex]CO_2[/tex] = [tex]9.31\times 10^{-4}\ \text{mol/h}[/tex]

[tex]R_2[/tex] = Rate of diffusion of [tex]N_2[/tex]

[tex]M_1[/tex] = Molar mass of [tex]CO_2[/tex] = 44.01 g/mol

[tex]M_2[/tex] = Molar mass of [tex]N_2[/tex] = 28.0134 g/mol

From Graham's law we have the relation

[tex]\dfrac{R_1}{R_2}=\sqrt{\dfrac{M_2}{M_1}}\\\Rightarrow R_2=\dfrac{R_1}{\sqrt{\dfrac{M_2}{M_1}}}\\\Rightarrow R_2=\dfrac{9.31\times 10^{-4}}{\sqrt{\dfrac{28.0134}{44.01}}}\\\Rightarrow R_2=1.167\times 10^{-3}\ \text{mol/h}[/tex]

The rate of effusion of the [tex]N_2[/tex] gas would be [tex]1.167\times 10^{-3}\ \text{mol/h}[/tex].

Answer:

it is option c liner eclipse

Answer:

A-It is a lunar eclipse, in which the Earth casts a shadow on the Moon.

Answer: The pressure of the gas is 0.34 atm

Explanation:

According to ideal gas equation:

[tex]PV=nRT[/tex]

P = pressure of gas = ?

V = Volume of gas = 605 ml = 0.605 L      (1L=1000ml)

n = number of moles  = 0.00803

R = gas constant =[tex]0.0821Latm/Kmol[/tex]

T =temperature =[tex]39^0C=(39+273)K=312K[/tex]

[tex]P=\frac{nRT}{V}[/tex]

[tex]P=\frac{0.00803\times 0.0821 L atm/K mol\times 312K}{0.605L}=0.34atm[/tex]

The pressure of the gas is 0.34 atm

Answer:

To ensure that everyone enjoys using your pool, it is important to keep the swimming pool pH levels in balance at all times. If the pH is too high, it could cause skin irritation and corrode metal parts on the pool. If the pH is too low, it could create a situation where the chlorine in the pool isn't as effective.

Explanation:

Answer:

I don't see multiple choice, so I'll answer this based on what I have learned on my free time.

Explanation:

Usually, when a ton of Urine is in a pool, it can throw off the Ph balance, and can even damage human eyes. Trust me, it's happened to me one time. my eyes burned like fire.

Answer:

Explanation:

The major regulation, regulatory, and communicating system in the body is the nervous system. It is the foundation of all mental operation, including thinking, learning, and memory. The nervous system, along with the endocrine system, is responsible for controlling and sustaining homeostasis.

Image 1 shows that the sun is travelling from the left while image 2 shows that the sun is travelling from the right.

We know that the solar system is composed of the sun and the planets. The planets move round the sun in concentric circles and the sun is the focus. This is the heliocentric model of the solar system.

The moon is also a part of the celestial bodies and the light from the moon is dependent on the direction of the movement of the sun. We have to recall that the moon is a non luminous object.

Learn more about the moon:https://brainly.com/question/13538936

#SPJ1

It would be Ionic Compounds.

Answer:

Salinity is a measure of the 'saltiness' of seawater, or more precisely the amount of dissolved matter within seawater.

Explanation:

alto cumulus is the pic

Answer:

0.034 Liters

Explanation:

Answer:

extensive properties such as mass and volume depend on something like perhaps the amount of what's measured. physical properties can be measured without changing substance chemical identity.

metals are the elements which exhibit degree of metallic behavior is know as metals. non metals are such elements which do not posses any metallic behavior and mekkloids are those elements that posses some of the properties like metal. but they act either like metals or non metals n they also have the same physical properties

Answer:

the Earth rotates on an imaginary line called its axis and different parts of the planet are facing towards the Sun or away from it. it takes 24 hours for the world to turn all the way around, and we call this a day.

Explanation:

Answer: in the daytime the sun is out so the stars are not visible becuase the suns reflection! At night When you gaze at the constellations, every star produces an image that's the same size, but your retina isn't sensitive enough to respond to the outer parts of those images except for the brighter stars — which therefore look bigger than the fainter ones.

Explanation:

This is what I found on goog.le a while ago now it might actually help if I’m wrong I apologiz, I hope this was your quistion!

Answer:

Explanation:

Sodium bicarbonate,

NaHCO

3

, will decompose to form sodium carbonate,

Na

2

CO

3

, water, and carbon dioxide,

CO

2

2

NaHCO

3(s]

→

Na

2

CO

3(s]

+

CO

2(g]

+

H

2

O

(g]

Notice that you have a

2

:

1

mole ratio between sodium bicarbonate and sodium carbonate. This means that the reaction will produce half as many moles of the latter than whatever number of moles of the former underwent decomposition.

Use sodium carbonate's molar amss to determine how many moles you'd get in that sample

0.685

g

⋅

1 mole NaHCO

3

84.007

g

=

0.008154 moles NaHCO

3

Now, if the reaction were to have a

100

%

yield, it would produce

0.008154

moles NaHCO

3

⋅

1 mole Na

2

CO

3

2

moles NaHCO

3

=

0.004077 moles Na

2

CO

3

Use the molar mass of sodium carbonate to determine how many grams would contain this many moles

0.004077

moles

⋅

105.99 g

1

mole

=

0.4321 g Na

2

CO

3Sodium bicarbonate,

NaHCO

3

, will decompose to form sodium carbonate,

Na

2

CO

3

, water, and carbon dioxide,

CO

2

2

NaHCO

3(s]

→

Na

2

CO

3(s]

+

CO

2(g]

+

H

2

O

(g]

Notice that you have a

2

:

1

mole ratio between sodium bicarbonate and sodium carbonate. This means that the reaction will produce half as many moles of the latter than whatever number of moles of the former underwent decomposition.

Use sodium carbonate's molar amss to determine how many moles you'd get in that sample

0.685

g

⋅

1 mole NaHCO

3

84.007

g

=

0.008154 moles NaHCO

3

Now, if the reaction were to have a

100

%

yield, it would produce

0.008154

moles NaHCO

3

⋅

1 mole Na

2

CO

3

2

moles NaHCO

3

=

0.004077 moles Na

2

CO

3

Use the molar mass of sodium carbonate to determine how many grams would contain this many moles

0.004077

moles

⋅

105.99 g

1

mole

=

0.4321 g Na

2

CO

3

By using the given data, the percent yield for sodium carbonate (Na₂CO₃) is equal to 127.

Percent yield of any data can be calculated as:

% yield = (Actual value / Theoretical value) × 100

In the question actual yield of sodium carbonate is given, which is equal to 2.04 grams. And in the table theoretical yield of sodium carbonate also given, which is equal to 1.60 grams.

Now putting these value in the above equation, we get:

% yield = (2.04 / 1.60) × 100 = 127

Hence, percent yield of sodium carbonate (Na₂CO₃) is 127.

To learn more about percent yield, visit the below link:

https://brainly.com/question/11963853

The wavelength of the radiation : λ=5.792 x 10⁻⁸ m = 5.792 x 10⁻⁶ cm

Region of Ultraviolet

Given

A frequency : 5.18 x10¹⁵ Hz

Required

The wavelength

Solution

Frequency (f): the number of waves per second  

Wavelength (λ): the distance from one crest/one trough to another

Fast wave propagation (v): the distance traveled by waves per unit of time  

v= 3 x 10⁸ m/s

General formula :

v = λ.f

λ=v/f

Input the value :

λ=3.10⁸ : 5.18.10¹⁵

λ=5.792 x 10⁻⁸ m = 5.792 x 10⁻⁶ cm

Region of Ultraviolet (4000 - 10 A°, 4 x 10⁻⁵ - 10⁻⁷ cm,7.5 x 10¹⁴ - 3 x 10¹⁷ Hz)

Balanced equation :

ScF₂ + 2KBr ⇒ 2KF + ScBr₂

Given

Reaction

ScF₂ + KBr ⇒ KF + ScBr₂

Required

Balanced equation

Solution

1. Give coefficient

ScF₂ + aKBr ⇒ bKF + cScBr₂

Sc, left=1, right=c⇒c=1

F, left=2, right=b⇒b=2

K, left=a, right=b⇒a=b⇒a=2

The equation becomes :

ScF₂ + 2KBr ⇒ 2KF + ScBr₂

Answer:

3 atoms of O

8.57g

Explanation:

The problem here is to find the mass of oxygen in the compound and the number of atoms of oxygen.

 The formula of the compound is:

 NaHCO₃;

   Here we have:

      1 atom of Na

     1 atom of H

     1 atom of C

     3 atoms of O

So there are 3 atoms of O

To find the mass of oxygen , we use the molar mass of oxygen;

     Molar mass of oxygen  = 16g/mol

 Mass of oxygen  = [tex]\frac{3(16)}{84.01}[/tex]  x 15  = 8.57g

Answer:

Molar mass: 399.9 g/mol

The mass of iron(III) sulfate is 269 grams.

Explanation:

First of all, you have to find the molar mass of Fe2(SO4)3.

So you find the molar first for each element

However, there are 2 iron atoms, 3 sulfur atoms, and 12 oxygen atoms.(Don't forget the 3 outside the parenthesis of SO4).

So you do this

So the final answer is 399.9 g/mol

Second of all, if you want to find the mass of Fe2(SO4)3, you have to convert from formula units to moles. After that, then you convert from moles to grams.

If you want to convert from molecules to molecules, you have to use Avogadro's number. Avogadro's number is 6.02 x 10^23. Then if you want to convert from moles to grams, you use the molar mass. We already know that the molar mass is 399.9 g/mol.

Therefore, now use dimensional analysis to show your work.

Formula units in the beginning and the moles will cancel out.

But we need to use significant figures with the least digits(which is 4.05) So we round to the nearest whole number.

So the final answer for the mass of iron(III) sulfate is 269 grams(don't forget the units).

Hope it helped!

Answer:

E) Plants take carbon from the atmosphere

Explanation:

Plants are a vital part in keeping the air clean. They take in CO2, H2O, and sunlight to start processing photosynthesis. The carbon taken in by the plant still remains with it after it dies, thus, fossil fuels.  

Answer:

e is correct

Explanation:

Answer:

Answer:

B.) conclusion