+2
Barium has a positive charge of 2
Answer:
[ Ga ] = 1.163 E-8 Kg/m³
Explanation:
- %wt = [(mass Ga)/(mass Si)]*100 = 5.0 E-7 %
⇒ 5.0 E-9 = m Ga/m Si
assuming: m Si = 100 g = 0.1 Kg
⇒ m Ga = (5.0 E-9)*(0.1 Kg) = 5 E-10 Kg
∴ density (δ) Si = 2.33 Kg/m³
⇒ Volume Si = (0.1 Kg)*(m³/2.33 Kg) = 0.043 m³
⇒ [ Ga ] = (5 E-10 Kg)/(0.043 m³) = 1.163 E-8 Kg/m³
⇒ [ Ga ] =
The melting point of the sample if it is not dried completely after filtering the recrystallized product will have a broad range and will occur at lower range than the actual value.
What is melting point?
Melting point is the temperature at which the solid form of a given substance changes to the liquid form at atmospheric pressure. It is important because, by using the physical property of a substance the substance can be identified.
The sharp range melting point of the substance indicates the purity of the substance. If the sample is not dried completely after recrystallisation, the melting point will have a broad range.
Therefore, if the sample given is not dried completely, it will be impure and the decreases the melting point of the substance. So the actual melting point of the substance cannot be determined.
To learn more about the melting point click on the given link brainly.com/question/40140
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Answer:
pH = 7.233
Explanation:
Initially, the buffer contains 0.208 moles of NaHSO₃ and 0.134 moles of Na₂SO₃.
NaHSO₃ reacts with NaOH thus:
NaHSO₃ + NaOH → Na₂SO₃ + H₂O
50.0 mL of 1.00 M NaOH are:
0.0500L × (1mol / 1L) = 0.0500moles of NaOH added. That means after the addition are produced 0.0500moles of Na₂SO₃ and consumed 0.0500moles of NaHSO₃. That means final moles of the buffer are:
NaHSO₃: 0.208 mol - 0.050 mol = <em>0.158 mol</em>
Na₂SO₃: 0.134 mol + 0.050 mol = <em>0.184 mol</em>
<em> </em>
As pKa of this buffer is 7.167, it is possible to use H-H equation to find pH, thus:
pH = pKa + log₁₀ [Na₂SO₃] / [NaHSO₃]
pH = 7.167 + log₁₀ [0.184] / [0.158]
<em>pH = 7.233</em>
Answer:
1.0 x 10⁻⁸ M.
Explanation:
<em>∵ [H⁺][OH⁻] = 10⁻¹⁴.
</em>
∵ [H⁺] = 100 [OH⁻].
∴ 100 [OH⁻][OH⁻] = 10⁻¹⁴.
∴ 100 [OH⁻]² = 10⁻¹⁴.
[OH⁻]² = 10⁻¹⁴/ 100 = 1.0 x 10⁻¹⁶.
<em>∴ [OH⁻] = √(1.0 x 10⁻¹⁶) = 1.0 x 10⁻⁸ M.
</em>
