some one help please ​

Answer:

Reproducible by other scientists

The personal opinion of the scientist

Using vanable conditions for each test

Explanation:

Answer:

Showing results for Temperature (°C) 5 Heating Curve for Water 160 140 2 120 100 80 60 40 20 0 "-20" 1 2 3 4 5 6 7 Time (min) 8 9 10 At what temperature does the solid start melting?

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[tex]\pmb{\red{\boxed{\sf{Na_{2}O(s)+H_{2}O(l)\dashrightarrow 2NaOH(aq)   }}}}[/tex]

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The correct option for the process used to refine aluminum from its bauxite ore is option D.

D. Smelting

The reason why smelting is the correct choice is as follows;

Bauxite is the aluminum ore from which alumina, also known as aluminum

oxide, Al₂O₃, is produced. Bauxite is extracted from the topsoil regions of

some subtropical and tropical regions, and the Bayer process is primarily

then used to produce alumina from the bauxite.

Aluminum is produced from the alumina by an aluminum smelting process

known as the Hall—Heroult electrolytic process which involves the use of a

carbon anode and direct current to produce aluminum by reducing the

aluminum oxide

Learn more about smelting process here:

https://brainly.com/question/3444206

Answer:

Reducing sugars are sugars where the anomeric carbon has an OH group attached that can reduce other compounds. Non-reducing sugars do not have an OH group attached to the anomeric carbon so they cannot reduce other compounds. ... Maltose and lactose are reducing sugars, while sucrose is a non-reducing sugar

Answer:

The total mass of mercury in the lake is 631,542.7 kg

Explanation:

Question: The given dimensions of the lake as obtained from a similar question posted online are;

The surface area of the lake, A = 100 mi²

The lake's average depth, d = 20 ft.

The concentration of the mercury, C = 0.4 μg Hg/mL = 0.4 × 10⁻⁶ kg Hg/L

Therefore, we have;

The volume of water mixture in the lake, V = A × d

∴ V = 100 mi² × 20 ft. = 2,787,840,000 ft.² × 20 ft. = 55,756,800,000 ft.³

1 ft³ = 28.31685 L

∴ 55,756,800,000 ft.³ = 55,756,800,000 ft.³ × 28.31685 L/ft.³ = 1.57885675 × 10¹² L

The total mass of mercury in the lake, m = C × V

∴ m = 0.4 × 10⁻⁶ kg Hg/L × 1.57885675 × 10¹² L = 631,542.7 kg

The total mass of mercury in the lake, m = 631,542.7 kg.

Answer:

helloooo

0.164m * 100 = 16.4 cm

now multiplying all of em

v = 1,687.888

Answer:

"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."

Explanation:

When enthalpy is positive and delta H is greater than zero, this means that a system absorbed heat. This is called an endothermic reaction. When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction.

The sign of q for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings are gaining heat from the system, the temperature of the surroundings increases.

Learn more about the endothermic reaction here: brainly.com/question/6506846

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Answer:

b. They do not move through the rock cycle at the same rate

Explanation:

The rock cycle is the phenomenon used to describe the interrelation of the three forms in which rocks exists, and a rock is changed between forms due to the Earth's geologic process, such as erosion, weathering and plate tectonics

The rock cycle involves both chemical and physical transformation of rocks and therefore, the atoms and compounds make and cut connections, such that the rate at which each atom move through the rock cycle at different rate

Answer:

các oxit đồng khi nó tiếp xúc với không khí. nó phản ứng đặc biệt với oxy trong không khí (không phải hơi ẩm), và tạo ra nấm mốc

Answer:

(b) A and C belongs to same group.

(c) D is a non metal.

Explanation:

The Electronic Configuration of E is

[tex]1s {}^{2} 2s {}^{2}2p {}^{6} 3s {}^{2} 3p {}^{6} 4s {}^{2} [/tex]

Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].

El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.

Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.

Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.

Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:

[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]

Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].

Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:

[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]

En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]

Aprende más sobre la molaridad:

A

Carbon monoxide gas can be prepared in lab by heating formic acid or oxalic acid with conc. H2SO4.

Procedure: Small amount of oxalic acid crystal is taken in a round- bottomed flask and all the apparatus are fitted as shown in figure. When conc. H2SO4 is poured in the flask through thistle funnel and heated then a mixture of CO and CO2 gas is formed. The mixture of gas is passed through a bottle containing NaOH solution where the CO2 gas is absorbed by NaOH.

2NaOH + CO2 → Na2CO3 + H2O

The pure CO gas is then collected in a gas jar by downward displacement of water.

Answer:

for volume only liters can be used

Explanation:

Answer:

0⁰c , 5 mmHg

Explanation:

Because at this temperature we all know water can be in state of both solid and liquid and when pressure is decreased it can be in form of gas too

Answer:

The answer is "Option i"

Explanation:

In this question, only option (i) is correct, and others were wrong which can be defined as follows:

In option (ii):

[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]

It is the complete ionic equation.

In option (iii):

[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]

It is the combustion reaction but a not balanced equation.

In option (iv):

[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]

It is the  decomposition equation.

In option (v):

[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]

It is the complete ionic equation.

Answer:

113.17 g

Explanation:

This can be solved using the Ideal Gas Equation:

PV=nRT

First step is to calculate the volume of the cylinder in L:

V=πr²h

V= π (11.5)² (140)

V= π (132.25) (140)

V = π (18.515)

V = 58,166.588 cm³ = 58.2 L

Then, convert kpa into atm:

1 kpa = 0.00987 atm

108 kpa = 1.06588 atm

Then, plug all of your values into the Ideal Gas Equation to solve for moles:

(1.06588)(58.2)=n(0.082057)(294)

62.034=n(24.125)

2.571357513=n

Finally, convert the moles into grams

2N = 28.0134 amu

O = 15.999 amu

_______________

44.0124 amu

(2.571357513moles)(44.0124 amu) = 113.17 g

ANSWER

a. actual yield

Explanation:

The amount of product generated by a chemical reaction is its actual yield. This yield is often less than the amount of product predicted by the stoichiometry of the balanced chemical equation representing the reaction (its theoretical yield).

On changing the ratio of baking soda and vinegar changes the amount of carbon dioxide produced is true, because each species will depends on both reactants.

Chemical reaction between baking soda and vinegar is shown below in the attached image in which the formation of carbon dioxide, water and sodium acetate takes place. So the formation of carbon dioxide depends on the baking soda and baking soda reacts with vinegar to form sodium acetate so change in the ratio will changes the amount of carbon dioxide.

Hence on changing the ratio of reactants and vinegar changes the amount of carbon dioxide.

To know more about chemical reactions, visit the below link:

https://brainly.com/question/26018275

The steps involved in the manufacture of sulphuric acid by contact process:

(1) Sulphur (or iron pyrites) are burnt in air to form sulphur dioxide.

  S+O2→SO24FeS2+11O2→2Fe2O3+8SO2

(2) Catalytic oxidation of sulphur dioxide to sulphur trioxide.

  2SO2+O2V2O52SO3ΔrHo=−196.6kJ

The reaction is reversible and exothermic.

(3) Sulphur trioxide is dissolved in 98% sulphuric acid to form oleum (fuming sulphuric acid). 

  SO3+H2SO4→H2S2O7

(4) Oleum is diluted with water to form sulphuric acid of desired concentration.

    H2S2O7+H2O→2H2SO4

            and

Manufacture of H2SO4 by contact process involves three steps:

1. Burning of sulphur in air to generate SO2.

2. Conversion of SO2 to SO3 by oxidation with air in the presence of 

Answer:

the uses of exothermic reactions are:

1) lighting of stove

2) self heating cans

3) hand warmers

4) in some case exothermic process can be used to cook food such as rice  (by adding calcium oxide to water heat is evolved and it helps to cook food )

Explanation:

hope this helps you pls mark me as brainilst

Answer:

They are good electrolytes

Answer:

wat

Explanation:

Answer:

Answer:

Is water the only liquid? If not, name 5 more

Water, ethanol, household bleach, blood, paint, milk, gasoline, mineral oil, acetone and butyl alcohol are examples of liquids. Liquids' properties allow them to flow or be poured easily into containers, lava

water is not the only liquid.

Answer:

apple juice, milk, smoothie, blood, urine

Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens

Explanation:

Answer:

Explanation:

Put the given unit on the bottom of the brackets.

84 miles [tex]\frac{1 km}{0.6 miles}[/tex] = 84/0.6 = 140 km

Answer:

which energy?........

Explanation:

..........................

........

....

Answer: lithium- 3 protons, 3 electrons, 3 neutrons

Oxygen- nucleon no. 16, Atomic no. 8, 8 protons, overall charge (-2)

Sorry I don't the others. Hope this helps