Answer:
option A is correct ( sodium, calcium and barium)
Explanation:
Given compounds:
Sodium chloride , calcium sulfide, barium oxide
We know that metals form positive ions. In order to solve the problem we must identify the metals from given compounds.
Na⁺Cl⁻
Ca²⁺S²⁻
Ba²⁺O²⁻
We can see that sodium, calcium and barium contain positive charges.
Thus option A is correct.
Because sodium have one valance electron. When it combine with chlorine sodium lose its one electron to complete the octet and chlorine accept it to complete its octet. Thus sodium form positive ion and chlorine form negative ion.
Similarly barium and calcium are present in group 2. Both have two valance electron. When they lose them cation are formed.
Other option are incorrect because,
Option B have sulfur and oxygen which are anion.
Option C have chlorine which is also anion
Option D have chlorine, sulfur and oxygen that are anions.
Takes place in USA and Mexico
Answer:
126.0g of water were initially present
Explanation:
The electrolysis of water occurs as follows:
2H₂O(l) ⇄ 2H₂(g) + O₂(g)
<em>Where 2 moles of water produce 2 moles of hydrogen and 1 mole of oxygen.</em>
<em />
To find the mass of water we need to determine moles of oxygen and hydrogen, thus:
<em>Moles Hydrogen:</em>
14.0g H₂ ₓ (1mol / 2g H₂) = 7 moles H₂
<em>Moles Oxygen:</em>
112.0g O₂ ₓ (1mol / 32g) = 3.5 moles O₂
Based on the chemical equation, the moles of water initially present were 7 moles (That produce 7 moles H₂ and 3.5 moles O₂). The mass of 7 moles of H₂O is:
7 moles H₂O * (18g / mol) =
<h3>126.0g of water were initially present</h3>
Answer:
Explanation:
Look up the density of the material the object is made of in kg/m³.
Measure the volume of the object in m³.
Multiply the density by the volume.
You will then have the mass of the object in kg.
Answer: 1560632 joules
Explanation:
The change in thermal energy (Q) required to heat ice depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Given that:
Q = ?
Mass of frozen water (ice) = 1kg
C = 4184 J/(kg K)
Φ = (Final temperature - Initial temperature)
= 100°C - 0°C = 100°C
Convert 100°C to Kelvin
(100°C + 273) = 373K
Then, Q = MCΦ
Q = 1kg x 4184 J/(kg K) x 373K
Q = 1560632 joules
Thus, the change in thermal energy is 1560632 joules
