Question 1
Review
Which laboratory equipment is correctly paired with the unit it measures?

Answer - A, B, D, E

to prevent scheduling conflicts

to help meet deadlines

to maintain a consistent schedule

0.50 mol SiO₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

30 g SiO₂ (sand)

Step 2: Identify Conversions

Molar Mass of Si - 28.09 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of SiO₂ - 28.09 + 2(16.00) = 60.09 g/mol

Step 3: Convert

Step 4: Check

Follow sig figs and round. We are given 2 sig figs.

0.499251 mol SiO₂ ≈ 0.50 mol SiO₂

Answer:

[tex]\boxed {\boxed {\sf About \ 0.5 \ moles \ of \ SiO_2}}[/tex]

Explanation:

To convert from grams to moles, we must use the molar mass.

1. Molar Mass

Use the Periodic Table to find the masses of the individual elements (silicon and oxygen) in sand.

Examine the formula for sand: SiO₂. There is a subscript of 2 after oxygen, so there must be 2 oxygen atoms. Multiply oxygen's mass by 2 and add silicon's mass to find the molar mass of sand.

2. Calculate Moles

Use the molar mass as ratio.

[tex]\frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]

Multiply by the given number of grams (30)

[tex]30 \ g \ SiO_2 * \frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]

Flip the fraction so the grams of sand will cancel.

[tex]30 \ g \ SiO_2 *\frac{1 \ mol \ SiO_2}{60.083 \ g \ SiO_2}[/tex]

[tex]30 *\frac{1 \ mol \ SiO_2}{60.083 }[/tex]

[tex]\frac{30 \ mol \ SiO_2}{60.083 }[/tex]

[tex]0.499309289 \ mol \ SiO_2[/tex]

3. Round

The original measurement of grams has 1 signfiicant figure. We must round our answer to 1 sig fig.

For the answer we found, that is the tenth place. The 9 in the hundredth tells us to round the 4 to a 5.

[tex]\approx 0.5 \ mol \ SiO_2[/tex]

There are about 0.5 moles of SiO₂ in 30 grams.

Answer:

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch

and carotid arteries. These send impulses to either the cardioaccelerator or

cardioinhibitor center in the hypothalamus of the brain, which in turn sends an

impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a

feedback diagram to illustrate what happens to restore homeostasis when blood CO2

rises.

Explanation:

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch

and carotid arteries. These send impulses to either the cardioaccelerator or

cardioinhibitor center in the hypothalamus of the brain, which in turn sends an

impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a

feedback diagram to illustrate what happens to restore homeostasis when blood CO2

rises.

Answer:

Two elements

Hydrogen and Oxygen

Answer:

a

Explanation:

Answer:

D

Explanation:

Answer:

Sound waves travel through matter

Explanation:

Higher amplitude sound waves are more likely to be transmitted through matter instead of reflected. Lower amplitude sound waves are more likely to be reflected or absorbed, resulting in a lack of an echo. Sound can travel through air, water, and solids

Answer:

O energy is quantized

Explanation:

Bohr's model of that atom attempts to explain the idea that energy is quantized within an atomic space.

Answer:

Eliptical

Explanation:

While some orbits may seem circular, like Earth's, it is still an ellipse. Planets orbit stars in an elliptical shape, but some come very close to perfect circles. As for the other two, im certain you have never seen a triangular or spherical orbit. Hope this helps.

i think the answer is b) i.e. Switch....

according to me ammeter and battery are already there...

Answer:

Chemical Energy is energy stored in the bonds of atoms and molecules. Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy. Chemical energy is converted to thermal energy when we burn wood in a fireplace or burn gasoline in a car's engine.

MARK BRAINLIST PLZ NEEDS ONE MORE

Explanation:

Answer:

Mosquitos can stand on water because;

A. The mosquito is able to walk on the water due to the attraction between multiple water molecules, creating surface tension

Explanation:

Surface Tension is the surface property of a liquid which is due to the cohesive forces of attraction between its molecules, that enables it to withstand an external shearing force

The molecules in a liquid maintain a cohesive force between adjacent molecules that keeps all the molecules together such that the liquid has a defined volume

On the surface of the liquid, the cohesive forces between the molecules are shared by only between the adjacent molecules and molecules which are under the surface, and therefore, the attraction is much stronger such that the surface of the liquid is in tension, which is called the surface tension of the liquid

Therefore, the mosquito is able to walk on the water due to the attraction between multiple water molecules, creating surface tension.

a. t = 4.33 s

b. R = 53.04 m

c. H = 22.97 m

Given

vo=initial velocity=24.5 m/s

Angle = θ = 60°

Required

(a) time of flight, (b) range, and (c) maximum height.

Solution

Parabolic motion

a. time to flight

t = (2vo sin θ) / g

t = (2 x 24.5 x sin 60) / 9.8

t = 4.33 s

b. range (horizontal range) :

R = (vo² sin2θ )/g

R =(24.5² sin 120)/9.8

R = 53.04 m

c. maximum height

H = (vo²sin²θ)/2g

H = (24.5²sin²60)/2.9.8

H = 22.97 m

Answer:

10Rb° + 2RbNO₃  =>  6Rb₂O + N₂

Explanation:

Given:   Rb° + RbNO₃ => Rb₂O + N₂

=> 1st balance rubidium in RbNO₃ against Rb₂O  by inserting a '2' coefficient before RbNO₃ and a '6' coefficient  before Rb₂O

=> Rb° + 2RbNO₃  =>  6Rb₂O + N₂   => Oxygen and Nitrogen are balanced. All that remains is balancing Rb by inserting a '10' coefficient.

=>  10Rb° + 2RbNO₃  =>  6Rb₂O + N₂

Note: In balancing chemical equations, saving an element that is not part of a compound until last frequently gives balance by inspecting the number of elements of the specific kind and boosting its coefficient to balance the equation.  

Balanced equation =>  10Rb° + 2RbNO₃  =>  6Rb₂O + N₂

The balanced chemical reaction can be of the equation given is [tex]2Rb + RbNO_3 - > Rb_2O + N_2[/tex].

We need to make sure that the amount of atoms of each element is the same on both sides of the equation in order to balance the chemical equation [tex]Rb + RbNO_3- > Rb_2O + N_2[/tex].

By counting the atoms in each element, we may begin to balance the equation. We have one Rb, one Rb, one N, and three O atoms on the left side. We have two Rb, one N, and two O atoms on the right side.

We can add a coefficient of 2 in front of [tex]RbNO_3[/tex] to balance the Rb atoms, which gives us:

[tex]2Rb + RbNO_3 - > Rb_2O + N_2[/tex]

Thus, now, the equation is balanced with two Rb atoms on both sides.

For more details regarding chemical reaction, visit:

https://brainly.com/question/34137415

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Answer:

332g

Explanation:

Given parameters:

Formula units  = 2 x 10²⁴

Unknown:

Mass of the compound = ?

Solution:

The formula of the compound is:

            CaCO₃

      6.02 x 10²³ atoms are contained in 1 mole of a compound

       2 x 10²⁴ atoms will be made up of [tex]\frac{2 x 10^{24} }{6.02 x 10^{23} }[/tex]   = 3.32mole of CaCO₃

 Mass of CaCO₃  = number of moles x molar mass

      Molar mass of CaCO₃  = 40 + 12 + 3(16) = 100g/mol

 Mass of CaCO₃  = 3.32 x 100  = 332g

Answer:

4.43 g

Explanation:

The reaction between sodium chloride and flourine gas is given as;

NaCl + F2 --> NaF + Cl2

From the stochiometry of the equation;

1 mol of NaCl reacts eith 1 mol of F2 to form 1 mol of NaF and Cl2

Mass of 1 mol of F2 = 38g

Mass of 1 mol of sodium flouride, NaF = 42g

This means 38g of flourine reacted with NaCl to form 42g of NaF

xg of F2 would form 4.9g of NaF

38 = 42

x = 4.9

x = 4.9 * 38 / 42

x = 4.43 g

Answer:

71%

Explanation:

Answer:

4.00L

Explanation:

Using Charle's law, which have the following equation:

V1/T1 = V2/T2

Where;

V1 = initial volume (litres)

T1 = initial temperature (Kelvin)

V2 = final volume (litres)

T2 = final temperature (Kelvin)

According to the information provided, T1 = 275K, T2 = 400K, V1 = ?, V2 = 5.82L

Hence, using the formula;

V1/275 = 5.82/400

400 × V1 = 275 × 5.82

400V1 = 1600.5

V1 = 1600.5 ÷ 400

V1 = 4.001

Therefore, volume of the gas before it is heated is 4.00L

Answer:

How many molecules of water are there in 54 g of H2O H 2 O ? Solution. Molar Mass of H2O H 2 O = 2 + 16 = 18 g/moles. So ,number of moles of H2O H 2 O = Mass/Molar Mass = 54/18 =3 moles. Now 1 moles = 6.022×1023 6.022 × 10 23 molecule.

THe correct answer is heat

Answer:

hi

Explanation:

heat

Answer:

direction

Explanation:

A P E X

Answer:

The Soufriere Hills volcano has formed where magma is actively seeping up from the mantle to the surface. Soufriere Hills volcano is part of an island chain that formed at the boundary where two oceanic plates converge. One plate subducts beneath the plate with the island chain, and the subducting plate melts in the mantle and creates magma that rises and fuels the Soufriere Hills volcano.

Explanation:

Answer:

b

Explanation:

Beryllium is under Group 2, and group 2 are usually known as alkaline earth metals.

Answer:

2

Explanation:

Answer:

c = 0.898 J/g.°C

Explanation:

1) Given data:

Mass of water = 23.0 g

Initial temperature = 25.4°C

Final temperature = 42.8° C

Heat absorbed = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Specific heat capacity of water is 4.18 J/g°C

ΔT = 42.8°C - 25.4°C

ΔT = 17.4°C

Q = 23.0 g ×  × 4.18 J/g°C × 17.4°C

Q = 1672.84 j

2) Given data:

Mass of metal = 120.7 g

Initial temperature = 90.5°C

Final temperature = 25.7 ° C

Heat released = 7020 J

Specific heat capacity of metal = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 25.7°C - 90.5°C

ΔT = -64.8°C

7020 J = 120.7 g ×  c ×  -64.8°C

7020 J = -7821.36 g.°C ×  c

c = 7020 J / -7821.36 g.°C

c = 0.898 J/g.°C

Negative sign shows heat is released.

Answer:

22.4 L

Explanation: